I think Noelle is much better for a girl. I always liked it. It does seem just a bit odd to see it on a girl not born around Xmastime, but that's only because it is already established a reputation as a name for Xmastime babies. I have a cousin born then whose name is Holly Noelle.
But it's really no stranger than a girl named April who was born in August or November. Popular across the board. Though it doesn't seem to get much use now.
I guess it depends on what religion and how strongly the parents feel about it. In general I say it's not strange.