I went through a brief
Muirne phase a whole ago. I still do like it. That's a lovely image that you get from it. To me it's very warm, and makes me think of someone with red hair in a beautiful red ballgown. Not unlike the one that caelex posted in that ridiculous things you want thread, but less gothic-y (I have that dress on the brain right now!). It's a very elegant name.
I also like it better than its Anglicized versions, although I do think
Myrna and
Morna are pretty. I rarely say anything isn't usable. Sure, Murine would have some issue, but it's not that foreign looking or sounding.