hen pecking in anger?

hi
i am new to chicken keeping.  I bought my first two pol warrens on saturday and let them out on the garden today, not sure if i was a little hasty.  Anyway, one is larger than the other and seems more confident in coming up to you.  I picked her up and stroked her and my 5 year old stroked her too, she's really taken to them.  As I put the hen down, my 5 year old went to stroke her again, but the hen launched itself at my 5 year old and just  missed her eye, just made a mark on her cheek.  Think the hen was just saying leave me alone, but its obviously made her very wary.
My 5 year old had been out with them in the morning (just playing out in the garden, not touching the hens) and the same hen kept coming up to her and pecking her coat and following her, which I thought the hen was being friendly.  I'm not sure i can trust it being out on the garden at the same time as my daughter now.  And will it do it again......? 

Oh dear
Maybe best to teach your little to throw the corn as far as she can?  My lots love to scratch around hunting for the corn, and it keeps them out from under my feet, when I am working in there.