This, this exactly. He looks at them and he sees Ariana and Albus, as everything should have been, maybe as everything would have been if Ariana had never been attacked. (He doesn’t see a single thing of Grindelwald in them, in fact, he flat refuses to see anything of Grindelwald in them and he will never let that fucker lay hands on them…)
How much do you want to bet that it was Aberforth who was taking care of Albus during his pregnancy, even though the wounds from that summer were still so fresh? I can imagine that Albus maybe tried to hide it at first; he’d already done so much to hurt his family and besides, Aberforth had made it clear that he doesn’t want anything to do with Albus anymore (his nose still aches a bit at times), it will be fine, it’s only nine months, he can handle this on his own (he can’t handle this on his own).
After three months or so of no contact, Aberforth finally dregs up enough worry to go check on Albus where he has wandered off to (for some reason, I’m imagining a small flat somewhere in Scotland, obviously in a Wizarding area) and when he sees the state that Albus is in when he finally manages to track him down, well….needless to say, Aberforth hits the roof and it’s all he can do to keep himself from finding that bloody German bastard and throttle the life out of him. The only thing stopping him is that Albus, Albus has obviously not been taking care of himself like he should be and so it is up to Aberforth once again to take care of one of his siblings. And to make sure that German fucker stays blissfully unaware of what he has done….