Well, I'm glad I can help. When I needed help back in 2000, a site like this helped me. I'll never forget what that felt like, to have a place to go to where people "got" it.
Double vision isn't fun but the worst part about MG is having generalized weakness that gets worse or swallowing or breathing that does. Avoiding an MG crisis is a big goal for anyone with MG.
I won't bore you with details but I had MG my entire life but simply passed my physical inadequacies off as my "normal." It wasn't until my B12 deficiency in 1997 - 99 that my MG symptoms got markedly worse. I didn't figure out until March 2000 that I had ptosis. Now that's denial.

Going almost 40 years not knowing you have a disease. I was misdiagnosed at age 10 with lazy eye, when it was really MG.
Don't worry, your sister will get VERY good help from Dr. Sanders. And, yes, they will WANT to do testing on your other family members.

But will
they want to do the testing!
Annie