I am sorry to hear about your chiweenie. I wish they had said to strictly crate her from the beginning. A disk problem in the neck can be serious. If there is a disk problem in the back, it can affect the hind legs, bowel and bladder. A disk problem in the neck can affect all of those, plus the front legs and the muscles that control breathing. It can sometimes cause unmanageable pain and your choices are emergency surgery or putting the dog to sleep.
If you trust the vet and can afford it, I would leave her at the vet for a while. They are having to express her bladder to help her urinate, and you may not ever have done it before(?) Any owner can learn to do it, but I would rather not have to learn while my dog has a neck issue flaring up that could be aggravated. I assume they are expressing her on her side lying down, but I don't know. If you really feel you need to bring her home, I would recommend setting up an appointment where you go in and they teach you to express her bladder and you actually do it successfully right there in the hospital. That way you can be sure there will be no struggles when you get home.
Normally if the owner gets home and finds they are unable to express, they can carry the dog back to the vet to be expressed, but it would be much better not to have to do that with a dog with a neck problem. All the carrying and driving won't help her neck heal. If you could wait to bring her home till they get her a little more stable, that might be worth considering. Here is some information about setting up a crate for her when she is ready to come home and continue her rest.
They do make wheelchairs for dogs who cannot use their front legs. I think they are more often for dogs that are front amputees or have front leg deformities. But right now she needs absolutely strict rest and she needs to be handled like eggs. She is in a high risk condition right now, but hopefully the steroids will help the swelling in her neck to go down and her front legs will improve. It takes time. When a disk problem is treated with crating, they recommend crating for 6-8 weeks. I would think right now they are waiting to see how she responds to the medication.
If you find yourself in a situation where they say she needs surgery and you can't afford it, there is a loan available for emergency veterinary care through www.carecredit.com. Many vet clinics will have the application at their reception desk and you find out right away if you are approved. You can pay it off over time.
You may want to look at some of the information on Dodger's List. They specialize in doxies with disk problems, a chiweenie will fit right in. www.dodgerslist.com