I would be tempted to give this person another chance. My first thought was that she may have been a little miffed that while she was trying to talk you into the exercise program you weren't honest with her at that time.

She may have been embarrassed that she didn't notice, even tho you say there is nothing to notice.

If you liked her and her husband then I say invite them over, after dinner tell her how sorry you are that you dropped the bomb about MS and ask her if she has any questions about you and the disease and then get on with the building of a new friendship.

That's just my humble opinion but if you truly did not like her for other reasons then no reason to pursue a relationship I guess.