Wanted to PM but that doesn't seem to be available here.
Oh well... Suggest you do some reading about it all. The FAB is good:
http://www.fabcats.org/breeders/info...rturition.html
And whilst needing help is very unusual with cats, do make sure you have all the information about your vets out-of-hours service - it may be somewhere you have never been before, and an emergency dash with a cat having problems isn't the time to start finding out exactly where it is.
Switch your girl to kitten food now, and keep her on it while she is feeding the kittens.
You've already had the advice to keep her on her own for the last few days until she gives birth, and let her have plenty of bedding. However not anything that kittens could get tangled in - cut-up old towels can be very dangerous. Fleece is great as it's safe and very easy to clean.
Also keep an eye on her as she gives birth and in the few days afterwards - there should be a placenta for each kitten, if she doesn't break the cord you will have to do it (break it, don't cut it) as leaving the kitten attached to the placenta can lead to all sorts of problems.
If you have accurate kitchen scales (the electronic ones that read to a gram are great) give each kitten a quick weigh each day but don't handle them otherwise in the first week or so. It's common to lose some weight in the first couple of days but then they should be putting a measurable amount on each day. The kitten my friend's Siamese had double his birth-weight in his first week, which is typical, and had tripled it at the end of three weeks. Stopping gaining weight is often the first sign of a problem.
In the first week especially they do very little but eat and sleep - if there is a lot of crying they may not be getting enough milk. Again this is very unlikely, but if it does happen bottle-feeding tiny kittens is a real skill as they don't have a cough reflex so it's horribly easy to let milk go down the wrong way.
If you haven't dealt with fleas and worms do so PDQ - the vet can supply products that are safe and effective for pregnant females, and advise on suitable pest control for the kittens. Hopefully her vaccinations are up-to-date - if not discuss that as well with the vets.
Make sure you have a low-entry litter tray for once the kittens arrive - once they start toddling (about 3 weeks) they will start to investigate it, and soon after to use it.
There should be no need for you to wean them so long as suitable food is often available - my friend's kittens used to start by swimming in the wet food and cleaning themselves up afterwards! (they often missed a bit - yuck) We noticed that the biggest litter (8 kittens) started on the food sooner than the small one (6 kittens). BTW these were pedigree British Shorthair kittens.
Once they are 3-4 weeks old visitors are good for them, so long as the visitors are calm and careful where they tread. it's good for the kittens to meet plenty of different people, other animals (if possible) and common household things like vacumn cleaners, brooms, washing machines and so on.
Finally I would never give a kitten away unless to someone I knew very, very well. My view is that firstly rearing kittens costs money - extra cat litter and food for mother and kittens at the very least - and takes time and effort. (OK I confess that once the kittens are playing with each other it's really hard to not watch!)
I'm also of the view that someone who can't afford £50 for a kitten with some planning will be totally unable to afford emergency vet care, should that become necessary. There's no NHS for pets. The RSPCA will give some help to people on benefits, but I'm not sure how much that can be counted on. If the pet became seriously ill it might be necessary to sign it over to a rescue to get it treated - and how upsetting is that? Some people insure, some put the insurance money into a savings account for the cat, some self-insure as they have plenty of savings. But there needs to be some sort of plan about how unexpected vet bills will be dealt with.