I would love to see
Athena used on a real child. I see it mentioned a lot by mythology lovers, but I've never heard of it actually being used.
Artemis is beautiful but nowadays it's too caught up with
Artemis Fowl. Maybe the association could be overcome: I don't know.
Freya is upcoming and trendy in some places.
Branwen is easily usable.
Guinevere is a bit trickier. Sounds very high and mighty and untouchable.
I'm unfamiliar with
Nephthys and
Ixchel, so my first reaction is "they are strange and too mythological-sounding"