OOO OOOO It's me!!! I have EDS, CFS, RA, and peripheral neuropathy, as well as a bunch of other things.
I was diagnosed by a geneticist, my primary thought I had lyme. I have it severely as well. I am on Disability (I am 23 and mentally fully functional) I can work minimally so I do this for my sanity, but find any shift longer than 4 hours and I require a day to recover. Due to working retail for so many years I have fluid on the knees that cannot be removed and it sucks so I have to be very careful.
W@hich type does your sibling have? The catch with EDS is that while it is genetic it is not type specific, so if she has hypermobility type, her parent could have had another type, or you could have another type. It is more common in females due to the way the genetics of it work. I've done a lot of research on this and have taught my Dr's a LOT.
If you have questions please please please PM me, EDS in its own right is not very common, also I've found that it is often paired with CFS and the Arthritis and Peripheral Neutopathy can actually be caused by it.
Anyways like I said, PM me with any questions so I can know how to direct my answers.
Oh and there is a lot to considder with surgeries or pregnancies, which could become an issue.
Connie-
The process of diagnosis is measurements of hypermobility. They also measure places like your ears (my tell tale sign is that my ears do NOT curl over on top they are flat like elf ears) You have to have x out of x symptoms to be diagnosed. They can also preform a skin biopsy (which BITES as in general local anastetics do NOT work on people with EDS) which can show them a marker dependying on the type you have. My type however has no marker.
ETA: here Connie
http://www.ednf.org/abouteds/index.php?option=com_content&task=view&id=29&Itemid=32