i would keep an eye on it but i wouldnt worry too much - the averages are just averages and you need people at the 1st percentile and people at the 99th to make the 'average' iykwim. it could just be her natural build. she seems to have a good diet - maybe if she ate alittle more lunch? but it is great she likes healthy things and is active - and if she is otherwise well then what can you do? is she in proportion (ie height and weight?). i am sure it is hard not to worry.. but i dont think you need to be too concerned.