Nine months is very young, but it really shouldn't kill her. Any puppies will NOT be registerable, though.
Do NOT let her get bred again, hope for only one or two, and RECORD THIS DATE. You will want to watch her very, very carefully in 60 days, as soon as she starts acting like she's in labor (tearing paper, not eating, possibly loose bowel movements, laying around and panting) time the labor. If she goes 3 or 4 hours with no first puppy, seems to be in any distress, starts looking tired, whines...ANYTHING, get her to a vet for a ceasarean instantly. And I do mean instantly, 3 AM, 4 AM, if you want her to live, don't sweat the vet bill.
She should come through that procedure just fine, though I would let her wait a year before breeding her again, limit her further litters to one a year, and personally, I wouldn't breed her more than 3 or 4 times max. Definitely stop by the time she's five.
This does not have to be a tragedy.