Is it possible for a young heifer that is in calf to go to a bull to be served?

NO!! No, no, no, no, no!! A young heifer (and I'm assuming that's a heifer that is around 6 to 12 months of age) should NOT even be in calf in the first place, nor should she even be serviced by a bull when pregnant! A pregnant should be at least 15 months of age when she is bred, and 26 months when bred again to produce another calf. Some people feel that a heifer should be 24 months of age when she is bred to have her first calf! But NEVER a young heifer, never ever ever!!

Get her aborted NOW. Inject her with some Estrumate or Lutylase IMMEDIATELY. Don't waste your time on trying to get a young girl like her to be producing a calf so young, you can afford to wait a few more months or longer!