Short term following the release from Gringotts
In the days and weeks that follow Harry and the Tonks family move into the duchy of Aquitaine onto a property shared with Gabrielle's family, initially the plan had been to have seperate and semi isolated houses on the property for each family and allow the Tonks family and Harry to come to terms with the new living situation that they had found themselves in. This however had changed in short order when they had realised just how far the machinations of the world intruded into Harry's life and the scope of the damage wrought by Dumbledore and the others.
With that in mind they had reassessed while Harry and Gabby had been spending their time together in the Goblin time room, and after discussion of the fact that Harry and Gabby were to spend what was to equate to much of a year together and likely become extremely close or to hate one another beyond all reason (which Appoline declared was decidedly less likely) the decision was made to have the housing be much more similar to a culdesac or late French manse with a shared courtyard.
This ultimately ended up being a very well considered decision as after the discussion between Harry and the Duchess on their leaving the Goblins hospitality it became immediately obvious that long and even short term separation was not going to work. Instead Harry and Gabby were in and out of each others rooms, spaces, and houses, more frequently than goblins made gold, and it was apparent to everyone involved there was no way to interfere in this given the two appeared literally connected by magic. This however did offer some unique teasing opportunities for both Fleur and Harry's new Sister She-who-must-not-be-named Tonks
Tonks in natural Tonks fashion had taken to having a 'baby brother' like a duck to water, if that duck was a metamorphamagus intent on terrorising the water at every opportunity. She had immediately declared Harry her newest subject on the road to world domination, something that had caused the watching Ted to laugh hysterically while Andi had seemed more solemn in the awareness that her daughter was perhaps not entirely joking.
Harry for his part was just glad to have more family that didn't despise him or want him dead and so having a new 'big sister' intent on actually keeping him around was more than enough to overlook the slightly chaotic nature of the elder girl. The only time he had truly feared her was when Andromeda had introduced them and the elder girl had made known her … dislike… of her first name with the insistence that not even a syllable of such should be muttered lest he find himself on her bad side, a bad side she assured him included the use of her abilities to gain revenge.
Not born an idiot Harry had immediately agreed to her demands and was quickly assured that the now second year girl would be more than glad to accept his fealty and offerings of all ice cream something that again earnt her laughter from Ted but not Andi.
Apart from meeting Tonks, he also came to meet Andi's husband Theodore, who insisted much like his daughter that ‘Ted’ would do. The man immediately made Harry feel at ease with him beginning to share embarrassing moments from the years of raising Tonks and some of the less graceful things Andromeda had done or said in her pursuit of getting him back and making peoples lives a living hell while doing so.
However unlike in the Dursley family where such things would be source for argument and fury, it turned out that these things were often points of pride for the Tonks family, once again assuring Harry as he had come to the realisation more and more since arriving that the magical world was completely insane and lacked common sense, especially when he learnt how Andi arranged for a entire company to go out of business just to affect Dumbledores sweet supply, or how she frequently encouraged Tonks to use her abilities to mess with the man despite chastising her for her pranking ways
Another unexpected effect of the proximity was that the Tonks and Delacour families became extremely close, in truest fashion this started with the kids, obviously in Gabby and Harry, but also in Tonks and Fleur.
Tonks and Fleur initially started rather adversarial on meeting for the first time, with Tonks being rather territorial about her new brother and Fleur being the same over her sister. Eventually however they each realised the other shared attributes that were already causing them issues in the wixen world, and came to terms, that and Gabrielle may have threatened to learn a way to create an anti ice cream ward to place on them both.
This caused both Fleur and Tonks to realise that the factors that made them different to other Wixen Fleur with her immature allure and Tonks with being a metamorph made them rather similar in how they were treated and quickly they became the best of friends often teaming up to embarrass their siblings and cause generalised chaos despite the threats of the anti ice cream ward.
It was this generalised chaos that lead the elder members of the families to become close as they were constantly trying to slow down or alleviate the mayhem and destruction that was a bored Tonks and Fleur. As it turns out after-all having a bored metamorph and a bored Veela both of which are already going through puberty and have limited targets was a recipe for disaster and chaos.
That the entirety of the Tonks family seemed to be themselves immune to the Veela Alure was another reason they became so quickly entwined, afterall it was rare for those born of Veela heritage to be able to find someone completely immune to their alure let alone an entire family of people immune.
As time progressed it was the combination of these factors that lead to the families spending nearly every waking moment back and forth coparenting and commingling, with them trading off responsibilities when either set of adults had to work and going as far as deciding that with the additional time and money they had available they would instead be schooling the children in the duchy, bringing in tutors as needed.
It was this decision that initially caused the most problems as both Harry and Gabby were insistent that if Fleur and Tonks were able to be schooled at home they should be as well. Several arguments were offered and rejected as to the reasons this was not possible, with the simplest of which being no one knew Harry was here and he was expected to attend Hogwarts to which Harry responded that was hardly necessary after what the Goblins taught them. The other was that both Harry and Gabby were to young to have wands legally to which Gabby reminded them that they didn't need them given their slowly advancing wand-less magic and Harry's ability to seemingly turn random scrap metal into weapons capable of acting as magical foci. This was further dismissed when Harry pointed out that according to the most recent laws the goblins showed them during their learning that there was a provision for a wixen last of their line to have access to a wand early and have the restrictions on underage sorcery lifted, something he had already taken the liberty of having Ragnark file for him.
This action itself caused several arguments as Andromeda and Appoline both disagreed with Harry and Gabby just contacting the goblins like that without even discussing it with them. This was countered by the wording of the deal with the Duchess and then rearguard that they weren't technically emancipated yet, and ultimately culminated in a several day period of arguments and short tempers, something that only alleviated after both sides managed to regain their cool.
Ultimately it was decided that while they might qualify for wands early they would not be allowed to get them until they were eleven and until then they could read and research whatever they wanted as long as the adults had checked it over first to make sure it was safe.