Okay, not sure quite if they would work or not but putting up the offer to see what you think!
I wanted to offer Serenade for Pina as a potential mate. (Once she grows up, of course.
Bowl.)
Pina already feels (I hope!) a teeny bit comfortable with Nightingale, Serenade's big brother. I was thinking they could meet through him. Perhaps when she's a kit (if you don't mind them first meeting when she's still a kit) she could be tagging along with Gale when he visits Pina. I figured a kit wouldn't startle Pina so bad, so that by the time Seren's grown up Pina will feel a bit easier around her. If you don't like mate-plots-where-adult-first-meets-plotted-as-a-kit things, we could try something with her as an adult. Maybe still through Gale. Gale could mention his friend who plays the piano is very shy and nervous, worse than him, and Seren would make her a bouquet of plants whose smells are pleasant and soothing and find a way to present it to her.
Seren's got a quiet surface. She seems a lot more cool and composed than she really is. Inside she's actually a totally loving sweetheart and willing to drain herself to the dregs to help someone. If she and Pina can establish a relationship, she'd be trying all sorts of herbs and such to try helping with her nerves. She has a magic with plants, not sure of its exact nature yet, but she'd be experimenting with different scents to see if any of those help and maybe calming drinks if she thinks it wouldn't hurt Pina more than it could help her. She's got patience and would be willing to take care of Pina.
How this turns into a romance thing, not sure yet. Wanted to see if you were even interested first, cause I imagine we'd be working out ideas for them if you are. This would most likely be pretty plot-intensive!
Also, if you think it really might not work out, no hurt feelings. I know Pina's probably gonna need something specific you're looking for that I might not have.