The party sounds amazing.
And I really like the idea of writing down everything you appreciate in Gia and your relationship, for her to see and for yourself as well. It works for me too, when I write stuff down or talk about it with someone, it usually sinks in better that way.
Me: bi female in my 30's
Partners: Hank, Dahlia and Fay
Metamours: Eddie (Dahlia's long-term partner)
Living with Hank, Dahlia, Eddie and rory (my ex/friend)