would a school keep Dd's place for a term?

[Akiko]

I am planning to move my Dd from her Prep school to a state primary from y5. However. I will have to give her current school one term notice. However, she has not have an offer yet, as no places are available at that school at present. She is on the waiting list.
My problem is, that if I give the prep school a notice and then a place does not become available, she will be left with no school to go to.
Has anyone had this dylema? Would the state school wait for a term and keep her place untill she is able to move?

If there is anyone else on the waiting list, no, probably not -if the place comes free, they will offer it to you if you are top of the list, but you will need to accept and take it up pretty much immediately or it will be offered to the next person on the list. If there is no-one else on the list, it should be fine, assuming no-one else joins the list in the mean time.

I can't answer the main part of your OP but have you considered the fact that some private schools are very flexible and when they know that you are waiting for another place give you some leeway. The prep school understandably won't want to end up with an empty space. So if you have given notice they might warn you off if there is another child wanting your child's place. So that you can reassess whether you want to withdraw you notice or take a calculated risk. Of course there are sadly other schools who are less flexible and would happily take a terms fees if you have not given notice and a terms fees from the new child in school. The latter situation is more normal as of course fee paying parents sign a contract to say they will give a terms notice or a terms fees.
I hope your prep school is one of the more flexible variety!