{Not to offend, but since you ask very specific questions that kinda nudge at the canon of this blog and form your own story outside of it, have you thought about writing fanfic? Not of the blog but, like, general Pokémon fic. You may have more creative freedom that way.}
Good to hear the chicks have been taken care of. Excellent work, anonymous!
That said, no, they don’t hold life debts, but sometimes, a pokémon may wish to befriend you if you show it kindness (which saving its life would count as). If that’s the case with this gardevoir, then I encourage you to pursue a friendship and congratulate you on a new partner!
However, because her skirt is actually a set of skin flaps, you can’t really make a new skirt to sew to the remnants of her old one. She might appreciate one to wear like a human would, though. Ask her to see what she thinks first, of course.
Best of luck!