Explain to her that prognosis is far less severe in this generation than it was when you were diagnosed due to the presence of modern drugs.

Take time to come to terms with the diagnosis. Try to maintain a sense of perspective as it's not necessarily something which will affect her that badly. We all have a different experience of MS. I was diagnosed over 30 years ago. Worked full-time until 9 years ago when I retired early after a very successful career. You need to be flexible & take the symptoms as they come. My advice would be for her to write a list of things she wants to do & do them so that if things get worse then at least you've done & visited places you wanted to go to. Live life to its fullest & (within reason & allowing for symptoms!) go for it!