Since she keeps asking, maybe she does want to know what you think, and will be glad if you're honest? At the very least when she asks tell her "Oh it's okay, it's just that there are names I like a lot better." And talk about those if she wants to.
Doesn't sound to me like she's that set on it, really.
From your list above we were on holiday a couple of years ago and heard an Amelie being shouted for all the time by her Glasgwegian father. Dh and I still snigger. Not that I am slagging Amelie btw its just with that accent.
Maybe like another poster said she say that you are unsure about it and then start talking about the names she was considering that you prefer. I think that names like Coutney, Tiffany etc were once quite posh but have become less so over the years. Perhaps she is trying to start a revival of sorts. Also perhaps she is questioning it a lot because she has doubts herself.
I would only ever ask my friend about a name if I genuinely wanted an answer... I also think T you can only offer an opinion before the baby's birth. In your position I would be honest IF she asks you again.