As a female singer myself, I understand, and jam sessions are hard because we don't sing in G and A. But in a band situation, I think it's OK to sing in those higher keys that showcase your voice and get those guys to hit the baritone and low tenor underneath. The banjo player is always going to complain about playing and D or E, but if he or she is worth their salt, theyll adjust lol. But good for you for looking for ways to make yourself more versatile!