It's interesting that your sister says people treat her differently when they find out she has MS; different people will react differently, I think. Some people have a hard time dealing with people who have any type of serious illness or physical challenge (formally called disabilities), becuz they feel so bad for them.
Conversely, that is exactly why some people seem to want to nuture them, albeit too much sometimes. However, I have seen people diagnosed with MS and other things (like cancer), who's attitudes have changed very dramatically, hence the varied reactions from others.
I have seen a range from constant rage and anger (which scares others); to perpetual selfpity-parties (which makes people feel helpless); to accepting their illness and doing the best they can; to those like yourself and one friend I have, who choose to look at life with a more hopeful and positive view: i.e. I am relatively well now, and am going to enjoy every minute of my life while I can.
Now, don't get me wrong, I understand that some people react differently to being diagnosed with something like cancer and MS (can't blame them really). I'm just explaining what CAN happen, and I feel GREAT compassion towards them ALL! I've worked in four nursing homes plus some group homes so I have worked with people with many different kinds of ailments like MS, CP, MD, and so forth.
I don't tell everybody that I have Spina Bifida; and it may only come up now and then. I prefer not to dwell on that, and I try to focus on all that I CAN DO, instead of the limitations, although they are real. Sometimes, I do have to talk about them becuz they do affect my life on a daily basis; and I suppose, this may even be more pronounced for someone with MS.
We had a family friend growing up who had MS and her name was KAY; and she was such an awesome lady. I felt so bad for her that she got this disease ~ I was only twelve y/o at the time and wanted to know why GOD had allowed that to happen to her (her husband was a minister). What was her response? She shared with me her hope in this way: she pointed to a plaque on the wall above the head of her bed that had THE SERENITY PRAYER ON IT! I never forgot that, and now I have one hanging in my home (a gift from a dear friend). That prayer has gotten me thru so much in my life!
Well, I know I don't have exactly what you want to know, but I just wanted to share with you that we just never know how GOD may be using us or YOU to give hope to others who have to deal with problems down the road. GOD used a lady who had MS to form an image of Eternal Hope in my childhood mind that has lasted my entire life ...
and Blessings to you and yours!