My soon to be 10yr old DD is believed to have HMS - long story short, lots of health issues over the years,
Stomach trouble, diagnosed as IBS
Skin/Urticaria Flare ups diagnosed as Exzema
Both it turned out were made much worse by steroid asthma inhalers, so improvement since coming off those, but still a bit of an issue at times
LOTS of various weekly, often daily aches & pains diagnosed as "growing pains" 
VERY bendy, even knowing little about the scoring system I can see she scores 6 or more on the required scale, but she's over flexible in other areas not mentioned, knees swing sideways etc etc
Way more than her fair share of accidents & injuries involving ligament/tendon damage, sprains & fractures :( - thankfully - if thats possible - most of these have happened at school or clubs, or I'm sure from the hospitals questioning we'd have had SS on our backs by now.
Bad injury a year ago had her seeing a physio for several months - she was lovely, VERY experienced said DD was hypermobile & hence the slow recovery & specialist care needed with physio - she can't "officially" diagnose HMS, I've been told that is a Rheumatologist -
GP refused referral, telling me not to project my own health problems onto DD
- I've asked several times & had similar fob offs
Gastro Doctor pulled her skin, which isn't stretchy & said she was fine & didn't need to see a Rheumy
Since then we've had yet more fractures due to over flexed joints & daily pains.
We even met a sports therapist mum at a garden party, whose own DD had been diagnosed that week & she asked me about DDs injury & turned out she recognised her as being like her own DD in her flexibility.
Thankfully DDs School have been great in working around this, but who's to say the next one will be, so a diagnosis is needed.
A few serious health issues over the years have taught me to trust my own instincts over our Doctors, DD wouldn't be here now - so I'm going back again to insist on a hospital referral tomorrow morning, but not expecting a good reception, so any tips or advice on how to get her to listen properly & get the hospital referral much appreciated
TIA :)