What did my friend mean by this?

hi. so yesterday, my friend was over at my house for a sleepover and we were in my room doing our nails and talking. i told her about this one time at school when this popular girl went up to my friend and said, "when i was talking to grace(not my real name) she started having a spazz attack!" obviously that didn't happen, she was probably just saying that to be mean. anywayz, after i told that to my friend she got all serious and was like, "well maybe you have epilepsy." and i'm like, "what?" and then she said that a lot of times people don't know when they have it. but i kept on telling her that i don't have it, and she said, "i'm not saying you do have it, but sometimes people have it but they don't even know." even she said that, it still seemed like she thought i did, so i asked her if she thought i had epilepsy. then she said, "i don't know, but last night while you were sleeping you got out of bed and started dancing and then got back in." that sounds like the worst lie ever, so i kept on saying that i didn't do that, but she kept on saying that it was true, cause she was like, "i'm not even kidding it is true." and she was sort of laughing when she said that. okay i'm pretty sure i don't have it, but what do you think she meant by all this, cause i'im kind of scared?