You need to talk to her, and determine why she is just using slim fast. She is running the risk of GI problems. The Human body is designed to use and requires a little of everything every day. You can go a few days (weeks even) Missing a few of the fat soluble vitamins every once in a while is ok, but some you NEED everyday. Fiber is definatly a daily requirement. It keeps everything moving and functioning like it should.... She wont get nearly enough in slimfast.
Does she have dentures? Is she having problems with the dentures? Are her teeth hurting her?
Master Guns Crittle, You out there??
"A human being should be able to change a diaper, plan an invasion, butcher a hog, conn a ship, design a building, write a sonnet, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, analyze a new problem, pitch manure, program a computer, cook a tasty meal, fight efficiently and die gallantly. Specialization is for insects." -Robert A. Heinlein