I dislike it strongly, unless it's the name of a female
German Shepherd. I knew a
Heidi who said she was glad that her parents didn't name her the other name they were considering,
Gretchen. I can't say that I agreed with her.
Now the reason that I always think of a female
German Shepherd is, I'm sure, that my family had a female
German Shepherd named
Heidi when I was a child. (My parents rejected my four-year-old suggestion of
Mary Ann.) But although if it weren't for that I might not have the
German Shepherd association, I still wouldn't like the name.