Hi Patience- my DD was tested for this at 7, so know exactly how you are feeling.
My DD's breast started growing, and had the Body Odour, but not the bleeding.
Gp referred us to a endincrinologist (sp) in the childrens dept of the local hopsital.
They give them a full body exam- check breast growth, look for pubic hair, and feel around the pelvis.
The main way they diagnose if extra tests are needed is by x-raying their left hand- this measures their bone age which can be different to actual physical age, and blood tests.
My DD had all this done and Consultant observed her with 6 monthly checks for a year.
By this time DD was coming up for 8 years old, and she was discharged, as they consider girls of 8 years and older 'normal' for starting puberty.
DD is 9 now(10 in March), like your DD is tall for her age (11-12 clothes) and is blossoming rapidly. Her periods haven't started yet though.
One other thing I will mention is PMT
DD also has symptoms of this- when I mentioned it to the consultant she okayed me to give her Evening Primrose Oil capsules daily - didn't really help with PMT (not severe) but it did help with DD's breast tenderness.Would be best to check with the Consultant before giving them though.
The only other thing I advise is talk to DD's school- they need to be aware.
My DD's school was great, they offered that she could use the Teachers toilets (as they have sanitary bins) and to use them to get changed for PE etc.
As for what I told DD- I told her all what was happening, and explained in simple terms about Puberty and Periods etc. It seemed to make it less scary for her when she knew what was happening. I also gave her a little purse for her school bag with Panty Liners in, just in case anything happens when she is at school.
I also found a downloadable leaflet had great info when I was scouring the net looking for info
www.childgrowthfoundation.org/psm.htm
click on the link on the right
and here
www.childrenfirst.nhs.uk/families/experts/p/precocious-puberty_faqs.html
has good info too.
Hopefully the Consultant will be able to help more- but I know how scary it is when you first hear about Precocious Puberty, and how it will affect your DD.
Good Luck