This has some A Starless Clan spoilers so read at your own risk.
So Sunbeam's perspective begins with a casual but adorable interaction with Blazefire, where it's revealed they are planning on becoming mates but it isn't official yet. I personally found them so cute, especially since Blazefire was more outgoing and Sunbeam is more reserved. Annnd then Blazefire decides he doesn't want to be her mate and that's that. (At least that's as far as I've gotten into River).
Apparently there's no ship art so enjoy Sunbeam.