FMLA ?'s

My wife has recently returned to work after a leave of 9 weeks due to the birth of our third child. Upon returning she was not returned to the same position and hours she held for the previous 3 or 4 years. She has been employed with this company for seven years and is one of the highest paid teachers at the center. She was informed that the hours didn't exist any longer and her position was appointed to someone else. I asked her employer if she hadn't left would she still have the hours and position before her leave? She replied, "Yes". There are other employees working the hours she had, so the hours do exist. My wife had 6:30am to 3:00pm hours to coincide with our other childrens school hours. She is also one of the highest employees in seniority and wages. In addition to these two incidences, she was informed that her anniversery date will be pushed back 9 weeks.This means she will not recieve her annual raise until then. Other employees have taken FMLA and returned to their same hours and positions that were temporarily filled. My wife is currently filling a position of a co-worker now on maternity leave. She was informed that she will have to relinquish these hours when that co-worker returns. I looked through the FMLA section and couldn't find anything directly answering these Questions. Can they legally move her anniversery date back regarding her raise and can they take her hours and position away? Ironically she works for one of the largest corporations in the childcare industry designed to assist working parents, yet we get no breaks or assistance.
Thank you!
Brian Wiegman