Sounds like your sister has Absent seizures (patite mal) I have had these type of seizures but they have gone away (so far) I don't really remember what happens to me when they happen so if you are in line or someone looks at you wierd when she is having one say what you want to say. MY DD told me she told people I was having a seizure and I would be okay in a minute. There is no reason for you to be embarassed of for your sister to be embarassed it is just a medical problem that can not be controled.
Make sure she stays hydrated that is the one thing that would make mine worse and stay as cool as possible. I hope you all have a great trip.
((((((((((((((((((((hugs)))))))))))))))))))
Jen
I will be traveling with my sister (45) who has epilepsy but is mostly under control. Sometimes she does encounter "black outs" (periods of time where she just stops what she is doing and cannot hear you when you are speaking to her or if she is sitting, she will put her head down and begin to hum.) If she is standing she will just sit down and have no idea where she is. The "blackouts" sometime last for a few minutes and when she comes out of them she sometines does not know where she is. How can we help her to have the best time at WDW and not feel embarrassed when these may occur. How can we help her if we are waiting in line for a ride and this happens? How do you explain this to other people who have never encountered this before? My sister has not been to WDW in over 25 yrs and I want this to be the best trip she will remember for life! A great big "Thank You" to all who reply. 
