She could very well have Syncope
, thats exactly what it sounds like. Its very sweet that you care so much about her. Is she being followed up by the doctor again? Or is she seeing her own doctor about this? Because if she isn't, then she needs to. What you can do to help is, when she has to get up from a lying or sitting position make sure she sits up first, and sits for a minute before standing. Its really a thing the doctors need to treat, so you just being there and supporting her is enough. It's really important that you don't try to diagnose her illness by searching the internet because this is very wrong and people are always making this mistake, leave it to the professionals. Take care.