Would workman's compensation cover carpal tunnel in MI?

My girlfriend of 4 years has been working at a Holiday Inn hotel in Michigan for about a year or two now. She is 20 years has no insurance or benefits, and makes barely more than minimum wage. She started off as a housekeeper, then was primarily a bed maker, and now she is a housekeeping supervisor who does all of the above.

Recently her right wrist has been hurting severely, and she has been dropping things without knowingly loosing her grip. She wears a brace to work sometimes and to bed every night, which helps, but it continues to bother her throughout the day. Also I believe both her Mom and Dad had the carpal tunnel surgery

Her wrist pain started off minor, but progressively is getting worse. When she first realized it to affect her negatively, (about a month after minor pain) she told the manager about it. The manager said something to the effect of carpal tunnel is hard to prove it happened from work, because it happens over time. The manager also said she has no doubt that her job has something to do with the carpal tunnel, but basically brushed her off by saying it is a hard injury to prove and it needs to be documented as soon as it happens.

Today, my girlfriend told me she is starting to feel it in her left hand as well. This really bothers me because she is only 20 and i know her left arm is going to get worse. She does a lot of bed making (sometimes 50 beds a day) so it really takes a toll. I told her to let her manager know immediately about the left wrist now, in hopes that they will actually try to do something because it has been mentioned when it happened. They will probably try to get out of it some how.

I think the holiday inn she works at is privately owned or managed, and they own/ manage a comfort inn which is right next to the holiday inn as well. I think they are awfully stingy over there, because she started at $7.50 an hour to be the housekeeper, and when she was promoted up to the supervisor, they only went up yo $8.00 an hour. I guess that isn't horrible, but now she does all of the work she did before, plus she has to call people on her own time regarding work schedules, and do a bunch of other tedious work. The head housekeeper and the supervisor she replaced both made $9.50 an hour, and they both did/do less work than her. When she asked about the $9.50, the hotel said they aren't doing that great financially so they couldn't do it (even thought they were ranked the best hotel in the area and are always pretty busy).

Since she has been working there, they have been adding much more responsibilities, without any incentives or pay increase. They make all employee's get there 15 minutes early, which they don't get paid for, otherwise they get "written up". Once in the 2 years she worked there she was actually 5 minutes late, but she called and let them know. Once she got in they wrote her up.

I guess my main question would be is she able to get workman's comp for this? We aren't looking for handouts, but I don't want her to be in pain anymore. If it would cover just the surgery to fix it we would be more than happy. I don't think its right that over exertion from her job is affecting her free time, and especially for such little pay.

Thank you for your time and answers.