Couldn't help but get a sense of dejavu when I read this..
About 6 months after my first child was born i started waking up every morning with sore feet & legs (Its a kind of stiff soreness)
After going to numerous Dr's and being told there's nothing wrong with me its just normal aches & pains, i eventually(a year later) found one who tested me for autoimmune disorders -
Autoimmune disorders arise from an overactive immune response of the body against tissues & substances normally present in the body. In other words the body actually attacks its own cells. The immune system mistakes some part of the body as a pathogen & attacks it.
As autoimmune diseases are quite rare in children, your daughter most probably just has growing pains or restless legs syndrome.. but if it persists i would say get your pead to do an antinuclear body blood test just to be sure as it took a year before any Dr even thought of testing for this with me.
This site is also quite informative
www.pediatriconcall.com/forpatients/comm...immune_disorders.asp
Dr Patrick Dessein (Specialist physician) Rheumatologist at Milpark Hospital is fantastic.