Animals are amazing!! I can already see a bit of a callous starting to form in those x-rays. You cannot pin a pelvis, you have to plate it and I don't think there is a plate small/light enough to use in a chin pelvis. If this patient came in to see me, I would prescribe metacam twice a day and put her in a very small cage or carrier for 4-6 weeks. As long as she is eating and pooping, she will probably heal. It won't be perfect, but it will work!
It looks to me like the pressure that broke her pelvis was from the leg, so either she fell onto her side or was kicked on her side. It is a common fracture that we see in dogs that get hit by cars running across the road. I would be curious to see her follow-up x-rays in 4-6 weeks.