Special Needs Pets

I have a min pin who was thrown in a garbage can and left to die after someone broke 3 of her legs and her pelvis. When I adopted her she could not lift her butt off the ground at all and now she can almost walk normal . . .even though she can not feel her feet well. She also has no control of her bowels and must wear diapers. Does anyone have any advice on how to deal with the chaff on the diaper on her inner thighs. I have been recommended many things . . vasaline, diaper rash cream, lotion, but nothing is working. She is a 10 month old puppy and is very active. She has no clue she has a disablity and plays HARD with other dogs. She has a wheelchair but we are not allowed to use it now due to her front right leg not healing corecting and she has to wear a front leg brace. Also her back right foot on her nails she has worn them down so far one is bleeding . . she she must wear a bootie now too. WOW she has issues but WOW I love her and she is my baby!! I have heard from people . .just put her to sleep . . . if you met her you would never say that. She is the most wonderful loving dog I have ever known.