Definitely best for the baby to come when SHE is ready
I know that a lot of hospitals have rules now that don't allow you to be induced until 41 weeks as a ftm. Unless medically necessary. It's always best for your baby for them to come when they are ready
I think it's better for the baby of they're in there until your due date. But my health nurse has said to me that it's best for the baby to stay in your womb until at least 38 weeks. It would be very difficult for you to have your baby on the 8th because you can't really choose when you go into labour. Even if you were to be induced it could take a few days. Even if she isn't born on the 8th naming her after your nan will still be a lovely thing to do. :) I'm due on the 20th and my nan's birthday was the 26th so if she's born on that day I'm having my nan's name as her middle name.