Prissy may mean 100% feminine boys or girls, but I dislike the way it sounds, not a good name. This would be a name parents would put on kids to teach them to be weak and defenseless, when kids should be noble and graceful. Prissy sounds way tooooo much like a slang for my likings.
Poor kid. Some people don't want their kids to be successful, well adjusted adults with beautiful childhood memories. Name your kid 'Prissy' and tell me you're not a sociopath.
I don't like this name. The word comes to mind first, and next the slave from Gone with the Wind. I can just hear Prissy talking in a high-pitched voice. That's why I can't picture any Priscilla, except maybe a very, very old one, going by Prissy.