As with all cats, they are not at all predictable are they?! My cat has just had kittens and I moved her into a separate room (away from the other 4 cats) about 10 days before she had them. Of course, I wasn't sure when she would have the kittens, but I did read an article on the internet that said any time from the 7th week you can feel the babies moving around inside her. When I read that article, I immediately felt her belly and yes, I could feel them, 10 days later they were here.
Anyway, we have a built in wardrobe in this room (a bedroom we use as a study) so I cleared out the cupboard, lined it with newspaper, put a blanket in a basket and put the basket in a box (on its side so she's covered 3 sides but the front is open in case I needed to help!). She showed no interest in it until a couple of days before she had the kittens, in fact the night before she meowed at me to follow her and she took herself in there as if to give me a hint. Last Sunday morning I woke up and checked on her at 7.00am to find she'd had them all, all done and dusted, bit of goo in the blanket obviously but otherwise all very neat and tidy! (Good girl!)
So it is possible your girl will take to the nest when she needs to. All we did was ensure that she was in one room leading up to the birth, to keep her from the other cats and from going outside as much as anything, as I read that the mum cat can get a bit aggressive in the lead up. The other thing to look out for, which my cat did exactly as the 'text book' said, was that she was really restless, paced up and down and got very vocal the night before she had them, about 8 hours before.
But as I said at the start, cats don't like to be predictable. If I can help with any other pre-birth questions, let me know.
Good luck and keep us all in touch!