Kim's intended middle name. She was named Kim after Kim Novak, and her parents were probably going to name her Donna. It never happened, as Kim explains...

Kim about Donna

Actually, I quite like the idea of being called Donna. I like that name. I was gonna have that as my middle name, but then my parents forgot to put it on the form. (1)

Interview source

(1) Going Live, BBC (UK), April 7, 1990