Travel expenses for rental properties

My wife and I traveled out of state to do maintenance on our rental properties.  We also did maintenance on my mother-in-law's rental property (also in that out of state location).  I'm planning to deduct our travel expenses for our rental property work.  My mother-in-law is planning to deduct the cost of repair items, and capitalize the improvements made, but is there a way for her to deduct any of the time and travel expenses we spent working on her property?  Would she have to pay us for the actual labor?