I have worked in Nursery School for almost 20 years and have seen many variations on names. In choosing our daughter's name, we debated the origin spelling of Annwfn and the more common spelling of Annwyn. The latter won out.
My advice is to go with what your preference is. Noah is known as a boy's name in Canada and your daughter would forever have to explain her name, but as someone who grew up with Michelyn as a name, it's not always a bad thing to be unique.
However, I personally like Noa better. It looks feminine and is very unique -- I haven't had ONE Noa in my classrooms, but have had six boys named Noah. Three of those were in the past two years. I'd love to hear what wins out... are you expecting?