Martha has a sturdy yet slightly frumpy vibe for me. It's classic and underused. I've only known two. I went to high school with one. She went by Mop for some reason. The other
Martha was the dd of a co-worker and is about 28 years old now. That's still fairly young to be named
Martha. I think of it as mainly a name for someone much older.
Between
Martha Jane and
Martha Caroline,
Martha Caroline all the way. OTOH, MJ is mighty cute ...