***My hubby's suggestion "Are you in the Point Cook area?"....what a sweetie.
Lol, the first thing I did was open google maps to see how close you are, hehe. Unfortunately you're not as close as I had hoped, or I would have offered myself as a babysitter! If you decide you want your daughter to be at the birth, you could maybe think about hiring a trainee doula. I think they are much cheaper and I think many of them need the experience of just being at a birth. It's also probably good for them to get experience with birth where their are other children present as well.

Otherwise, I think the babysitter idea is a good one as long as you can get a chance to get to know the person first. Are there any playgroups or mothers groups where you could possibly get to know other parents that might be willing to help you out?