I think they sound great together. To me
Mairwen does sound a bit tomboyish despite it's meaning (like
Gwen), probably because it's a little foreign to me.
Starla sounds more modern in comparison though so it might not work if it's a medieval setting.
~☆
January Song Recommendation☆~
Palace - "
Heaven Up There":
https://tinyurl.com/ynu7mah6