Impact of diabetes on fall. How long will healing take?

PT at home can also do a safety assessment and recommend equipment to reduce risk of further falls, correct sizes and types of DME, and what is covered by your insurance and what is private pay. Medicare does cover rental costs of DME, but the process starts with PT recommending items to MD, MD writing order and submitting it to correct approved vendor, etc. MD staff and PTs know how to do this.
Dragging her feet and having swelling are both problems that can lead to more falls, damage to her swollen skin that can result in infection, etc.
A podiatrist can do nail care, skin assessment of legs to toes, and give you instructions on how to keep her skin intact.

Does she have a Podiatrist?

When she’s been seen by her doctor, ask how soon she’ll benefit from a physical therapy assessment.

Soft tissue injuries sometimes take longer to heal than broken bones. A physical therapist working in conjunction with your doctor’s input may be able to give you a more practical sense of what you can expect, especially since your mother s dealing with at least two difficult conditions.

Hoping you get some advice that will be helpful to her soon.

In general, diabetes slows down the healing process of the body. Everything takes longer to heal. Some lesions become chronic, last for months or even stay forever.

Definitely a question for the doctors dealing with the injuries.
I sure do wish you luck, but MD questions need MD answers; your MIL's doctor is familiar with her case, her underlying issues, her diagnosis and her prognosis. And all this understanding that, as my oncologist used to say "Medicine is anything but an exact science" meaning it often comes down to best guess.
Again, wishing you the best.