Where would you start to look into it - with the GP? She seems to get a lot of pins and needles too and cramp in her feet (I think she might be flat footed - DH is and when we saw a podiatrist when she was little - they said you can only really tell if flat foot when 4 to 5 - I don't think you can do much about flat feet, but maybe some types of shoes are better than others? - she often complains after a day of wearing her trainers - but not during the day).