Shel:
If you love it, then use it. Names are such a personal thing -
I LOVE, LOVE, LOVE the name Ashton (for a girl - long story short - fell in love with the name from watching the North and South mini-series from the 80's) - but I probably won't ever use it because of Ashton Kutcher - he ruined it for me 
- on the other hand - I could fix the spelling?!?!?!
Anyway - my point is - use what you love....
Have you read the books?? They are AWESOME
http://www.johnjakes.com/northandsouth.htm
I am trying to find them on ebook, but do have them in paperback. LOVE THEM and also have the entire North and South series on vhs
I think Gwenna is beautiful but love the above posters Gwena suggestion and meaning. Gorgeous.
I have boys with really popular names and boys with very uncommon names. My dd's name is very uncommon and spelt in a way that some find hard to say (it is Ameline which is the old french name for Emmeline) BUT that said, I didn't pick it because of popularity or lack of we picked it because we loved it. As we love all our children's names.
I do think her name is going to rise in popularity. I already saw a newborn Ameline on a parenting board I post on (My Ameline will be 1yrs old in two weeks) and one of my client's cousin who wanted an unusal french girl name and was told Ameline's name, named her dd Ameline. Go figure!
Gwena is beautiful go with it!!