I would open my mouth and ask . . . too often we never get a second chance to make a new friend in a situation like that. Not every encounter in life is easy, welcome, or even successful. If she is taken aback by your question you can always say "Excuse me . . . I am sorry. I guess my Multiple Sclerosis radar is malfunctioning today." But you could also be opening a door to a friendship with someone who may otherwise continue to wobble down the road feeling very alone and unapproachable . . .