Once FMLA runs out and an employer fires you, can you still continue to receive STD benefits?

My daughter suffers from chronic migraines and stress related panic attacks. Her employer started recording her missed time under FMLA, and last year her doctor put her on Short Term Disability leave. She just started receiving her ST disability benefits in January. If her Doctor doesn't release her to go back to work on January 22nd her FMLA time will run out, and her employer will let her go. Will she still be able to continue receiving her disability benefits from her insurance policy even if she's been released from her job? (if the doctor deems her still unable to work)
Up until her doctor put her on leave, they were trying to make it so intolerable at work, she would quit. That only added to her stress; making her condition worse.
Any help for this situation out there? I would appreciate it! Thank you!