Most anything she puts her mind to. Blind people do different jobs and even manual ones. May need some training, and usually the jobs that require more skill is more friendly though.

Contact your state’s department of rehabilitation. All states have a department dedicated to blind rehabilitation. They can get her services to help her get back to work. There are plenty of jobs that she can do, and maybe even her old job.

I am in Texas. Your friend’s mother can get assistance financially and rehabilitation services.

There's a bunch of advice here:

https://old.reddit.com/r/Blind/comments/afq5ep/my_best_friend_is_going_blind_from_usher_syndrome/