Hi there - I'm Dr. Sara - It sounds like you have had a difficult day and I'm sure you're very upset and nervous about what is to come with Nyah.
Based on your description it sounds like she has multiple potentially complicated injuries. The first step with any major trauma is to get the pet's breathing and cardiovascular status stabilized - this usually includes giving IV fluids, pain medications, and any other "life saving" treatments. This is where you are right now. Once she's stabilized and they are sure she doesn't have any imminent health threats, they will begin to make a plan to assess the orthopedic issues like broken bones.
Unfortunately, without examining her myself and seeing her X-rays and other diagnostics first hand, I cannot definitively tell you what to do. Because her injuries are so complicated, it would be inappropriate for me to try over the internet. The vet(s) that are caring for her now are definitely going to be the best people to advise you on what type of surgery, if any, is recommended and the expected outcomes or complications.
In general, it's a good idea to surgically repair fractures that involve long bones (like the femur) or joints (like the acetabulum). This helps to get the pet back on their feet as quickly as possible and avoid future complications like arthritis arising from joint fractures that were not repaired. If a pelvic fracture is minimally displaced, meaning that the bone edges are very close together or touching, it is sometimes managed medically with crate rest and time.
She is young and she's got that on her side. If she can be stabilized enough to consider your long term options on the fractures, that is a very good sign.
I sure hope things begin to look up for her soon. Please let me know if I can answer any other specific questions!