As someone who has been in almost exactly this situation, let me tell you how lucky she is to have you. I've had to handle this mostly on my own, and it's been a circle or two of Hell.
She may be right about her employer. As I became more disabled my supervisor pushed harder and harder to create situations where I would fail so he could fire me. As I was depressed about things (and struggling to deal with my illnesses and growing disability) I made one huge mistake - I did not document what was going on. Document everything. Help her do it. Document what time she took off and why. Document any change to her job that they make. Document any comment about her performance they make. My then-supervisor made some statements that are arguably illegal (like telling me that he had to change my duties [which is legal] because "you might wind up back in the hospital any day now and I can't depend on you" [which is illegal - you cannot base an employee's performance based on a health-related 'might-happen']). If I'd properly documented I could have sued.
I also didn't want to give up working. When I lost that job my doctor all but begged me to file for SSDI but I refused, insisting I could still work. I got another job... only to be fired for "being more disabled than you lead us to believe in the interviews" (which wasn't the formal reason, and only said behind closed doors, so they could deny it was ever said).
SSDI is not the end of the universe. First, it's something you pay into - it's meant as a safety net for those who become too disabled to do their current job. It's not supposed to mean "I give up," it's realizing that your life has changed. Second, it doesn't have to mean the end of working completely. I cannot work in my former field anymore but didn't completely stop. I volunteered for the first 3 years and now work part-time, completely online.
Lastly, about mobility devices -- I get this one. I fought tooth and nail having to use a cane, but had to give in because I kept falling over. Now that I can barely walk I had to give in and get a mobility scooter. I am still not comfortable using it, but it does give me the freedom to do things I cannot do otherwise, like get around at a farmer's market or go to a fair. I keep trying to walk. The pain gets insane. Then I stop leaving the house because it hurts to walk. A part of me recognizes this is a stupid and vicious cycle, and the depression aggravates that. But there's a part that realizes that with the scooter I can do things just like everyone else.
As for the counseling et al. If she doesn't want to take time off of work, look into counselors or therapists that work off hours. Some even work remotely (ie. do sessions over things like Skype). There's a big database at psychologytoday.com that's searchable. Other options include finding online support groups, mailing lists, or chat rooms. Or you could get her posting here. :)