Uh-oh. I've had a friend exactly like this one. My friend said she had lupus, a brain tumor, diabetes, MS (Multiple Sclerosis, which my mother-in-law has and I've seen the real thing, so I knew my friend didn't have it), and so on and so on. She kept coming over to my house begging for five bucks so she can go to either the doctor or the hospital. Guess where I see her spending my money? Paying off her other friends for their prescription medications, and getting marijuana.
Your brother's wrong... she's not hypochondriac. A hypochondriac would have this phobic fear about having illnesses or diseases. When they have ACTUAL symptoms of something tiny like a cold or a little bump on their shins, they'd go onto the internet (those would be cyber-hypochondriacs), find deadly diseases that COULD have these symptoms, go nuts and go to the doctor. Basically blow the whole thing out of proportion. A hypochondriac would actually get something real, but make a cold sound like an AIDS virus with all their paranoia... get me?
Your relative is NOT a hypochondriac. She actively fakes these 'injuries', and tells you that she was diagnosed with purely fictional diseases, like your brother did to prove a point. However, she actually has Münchausen syndrome. This is a syndrome, and in some cases a mental insanity, that has a person completely fabricate, lie, and make up diseases and illnesses left and right and in some cases poison themselves just so they could prove to their relatives that they were right about having something when they were faking...
Bottom line - hypochondriacs really believe they have the disease (blowing things out of proportion), whereas Munchausens lie about it to elicit sympathy, attention, money and everything else from everyone, more often from hospital employees. Unfortunately, she's a chronic liar because she likes the attention and she will never stop. One of those days, she'll actually hurt herself to "prove" that one of her lies were truth. She belongs in the psych ward, I'm sorry to say.