Well said kita, now stand back and wait for the ' I only asked for advice I didn't want a lecture' speech. And the 'my dog is well looked after and I would find good homes for the puppies with my friends and family' not to mention 'who do you think you are telling me what to do' -
Mitykat, if you don't even know the basic requirements for breeding how on earth will manage to mate, whelp and rear a litter of anything up to sixteen pups that will eat you out of house and home, **** for england and chew your home to bits before they leave at 8 weeks if you are lucky, or 6 months if you can't find homes, because most people don't want a Rottie with a tail any more. Thats if she whelped ok and didn't need a C section which she might not survive nor her puppies, and which might cost you anything up to �1,000, plus the price of the stud (�500 ish) for a decent dog.
Take advice from experienced dog owners/breeders, have her spayed and love her for what she is, not for how much you can make out of her. If you want another puppy buy one from the breeder you got her from.