help with learned behaviour nightmare

so millie and mia went to the vets on tuesday. millie had her xray of her stomache and there is no copper slug tape. vet says mia is not pregnant (great news). confirmed mia is definately female and both are booked to be spayed in 2 weeks time.

when we got them home they appeared to be bonded (amazing what a day together in the vets can achieve) and are happily playing together in the garden and today have started cuddling. problem is with mia's phantom pregnancy.

she still has her nest in her hutch (decided to leave her with it to stop her remaking it) but yesterday decided to make a 2nd nest in millies hutch as millie watched. i took all the fur and put it into her own nest and cleaned out millies bed and put them in thier own hutches for the night. got up this morning to find millie proudly sitting in her very own nest she had made over night. she has obviously learnt this behaviour from watching mia, so now i have mia (bald rabbit thinks shes pregnant) and millie (equally bald rabbit who knows she's not pregnant but thinks making a nest is a normal thing for her to do).

how do i stop this behaviour before it becomes an issue?

You can't really, it's best to leave the nest until they get bored of it - otherwise they'll just remake them. Once spayed the behaviour will go away of it's own accord.

Good new on the sexing and lack of pregnancy