Mum is from the Caribbean. On an island near Venezuela and her people travel back and forth there a lot. But yeah, she never meets people with her name. It's pretty uncommon.
Now Mark on the other hand is annoyingly common. Not only as a first name, but as it's a homonym I have been known to butt into conversations just because I heard the sound Mark (as in "I really wish I got more marks on this test" "Wait, who called me?") or completely ignore people because I thought they were talking about schoolwork.