The first question I have is what gestation table are you using? Most of the calanders from the semen companies use Holstein which is 280 days. With my cross bred I use 285 days. Angus is 283 , Hereford 288, Simm 286, and brangus is 290 days. Depending on the breed your heifer and which table you used, you may not be as late as you think. I would recommend to just let her calve when she is ready. If you induce you have a higher chance of having to assist her and a higher chance she will retain her afterbirth, which can delay getting her bred back. I know it is tough to be patient, but it i the best virtue when it comes to calving. I learned this the hard way when I was young and impatient, now I just let them calve when they want to and have way less problems.