That was two years after they’ve met, and constantly being in the presence of each other. As for the mate bond snapping in place let’s not forget that Cassian and Nesta slept together for who knows how many times and only on Solstice day, when they completely opened their hearts to each other did their bond snap in place. Az joined them only after they were able to cut the ribbon and they weren’t even in close proximity to each other. And that’s when u are wrong Gwyn together with Nesta and Emerie were mostly trained by Cassian. Again people might say that yes but they still spent much time together in training. After that Mor transported Gwyn to the library and she only got out two years later. Az in the meantime was still in love with Mor and also in a rampage killing the Hybren soldiers. She was literally just rapped and her twin sister was killed in front of her. Well first of all, yes Az met Gwyn 2 years ago, ONCE, and at that time Gwyn wasn’t in her right state of mind or body. Some say that Azriel has known Gwyn for 2 years already and the made bond hasn’t snapped into place. Gwyn even asked him if he sings and Az answered YESSSS (smth I think that people are not talking enough about). Gwyn is a nymph and one of her distinctive traits is that she keeps singing and Az is literally a shadowSINGER. She will love Az and everything about him and will also teach Az to love everything about himself. But Az’s real self is with the shadows which is exactly what Gwyn will do. Some say that no Azriel doesn’t like his shadows and that they disappear when he is with Elain and that she sees his real self. Sarah says that they dance whenever Gwyn is near and they start talking to Azriel’s ear.

These are all my opinions so feel free to disagree. So i made a list of reasons but be careful cause it contains spoilers.

Gwyn a court of thorns and roses