Ginger is absolutely correct. If a tie took place, more than likely she is pregnant. She's very young to have a litter, both physically and psychologically. It would be best in this case to spay her immediately before the puppies have time to really form. At that point, it's not much more difficult than a regular spay and she will recover from it uneventfully. It would be far less dangerous to spay her and take the litter with it than it would be to allow an 11 month old puppy to whelp a litter.
Ghilly
Yes it is.
But there will be little chance of her becoming pregnant if the two dogs during mating didn't 'tie together' properly.(When they get stuck, back-end to back-end, for any time from a few minutes to twenty minutes or so) If they did, you can bet she will be.