Welcome to ThisIsMS, Leila. You have found just what you were looking for – a community of people who understand .We are here to answer any questions that we can, to offer our opinions, to share our experiences, or just to listen if that is what you need.
We do not all necessarily think alike – my own ideas are quite unconventional: I think many MS symptoms can be traced back to excess insulin. I encourage every person diagnosed with MS to request a "fasting blood insulin test." I think this is the reason many have seen improvement with a regimen of diet and exercise, such as Dr. Terry Wahls and her experience (http://www.TerryWahls.com
Your love for your sister is apparent; it will sustain both of you through this journey. All the best to you and your sister, Leila.
My hypothesis: excess insulin (hyperinsulinemia) plays a major role in MS, as developed in my initial post: http://www.thisisms.com/forum/general-discussion-f1/topic1878.html "Insulin – Could This Be the Key?"