This is my name. Mine is spelt Jemimah. I'm in my late 20's. I can honestly say no one has mentioned aunt jemima to me or said I have a racist name
I have a fair few American friends and it has never come up!
As for puddleduck, yes I do get that, but it's never bothered me.
I mainly get Mimah or Jem or variations thereof from family and friends. It's a versatile name which I like! I didn't love it when I was in secondary school, didn't think it suited me, I'm working class northern and it felt a bit 'posh' for me but love it now that I'm an adult! I've only met 2 other Jemimah's so it's not very common but I believe it's on the rise! Go for it... it's a great name 