I imagine that two weekends together is not enough experience to know conclusively whether things are getting easier for you over time. Maybe you have enough experience with her visiting him alone that you know whether that gets easier over time (it's hard to derive from your original post).
In either case, it sounds like the three of you all have "the stuff" that long term polyamorous relationships are made of. Congratulations on finding your way forward to arrive at here and now. It all sounds very scary and intense and sincere and compassionate so far. Here's to hoping that you all find more of what you're looking for.