I suggest you line the bathtub with towels and blankets and allow her to give birth there. She can be easily moved when the kittens are born and is likely to stay where she is put unless it is totally unsutable for her. Set up a large box, or maybe trick her with a baby bath if you've got one?
Ziggy had her kittens under my son's bed. Well she definetly couldn't stay there, so I moved her. First I put the kittens in the box and left them for a while until Ziggy had come back to them. Then, I carried the box into my room and she followed. She was happy with that.
Make sure you move the main towel that has birthing fluid on it with the kittens and wash the others. That way she won't get confused the sent.
With regards to the milk. I'm thinking any day now
Milk will usually be able to be expressed 1- 2days before.
About the waters breaking. Ziggys went about 12hours before. Just saw this slightly bloody fluid dripping from her...
She didn't show any nesting behaviour and had too of the babies without me knowing!!! She hates my sons room, but it was peaceful at the time.