I dont love it but then its not my child but I dont hate it either.
I've heard worse names.
Also, its only when making birth announcements where people will hear the full name including middle name.
I know a lot of people have old fashion middles names like Ivy after Grandparents and the like. My middle name is my Nan's name.
So on the whole she'll be Blue Carter, which I said isnt that bad for a celebrity baby