Should I use bed rails if I am having trouble keeping my mom from falling out of bed?

Bed rails are not necessarily the safest solution. Is she sleeping in a hospital bed without rails? If so, perhaps an adjustable twin bed would solve the problem.

Does she toss and turn so much that she doesn't realize how close she is to the edge of her bed, and falls out as a result? Perhaps half rails or soft rails would be the answer.
Does she fall when she tries to get up to use the bathroom at night? Perhaps the solution is as simple as plugging in a very low wattage night light.

There are several options to consider when thinking about home safety such as falling out of bed. I suggest consulting with an occupational therapist who can evaluate and recommend several options that may be right for you and your mom: bed placement in the room, use of a floor mat to pad the landing if a person rolls out of bed, use of special cushions designed for positioning while in bed, recommend a hi-low bed which is like a hospital bed, but lowers all the way to the floor, as well as a variety of bed rail systems that are available.

Have a professional evaluation otherwise Medicare won't cover the equipment and the expenses can be enormous.