Ditto on the walker bag...or for wheelchair. I don't have MS, but am disabled (lots of hip replacement, dislocations, other surgeries, yadda yadda yadda, etc

) and have used crutches off & on for over 20 years and use them all of the time when I'm out of the house now. So, a bag of some sort for carrying things would be great, speaking from experience. Also, if a person uses walker or crutches fingerless gloves are amazing to wear (I should have been wearing athletic/weight lifting gloves for many years..but they are ugly...so...I knit pretty ones

)
I also think that anything that you knit from the heart is a wonderful gift even if you can't think of something that is helpful with her disability :D , although, that is a GREAT idea

!!!