SHE who wants friends must her self prove to be friendly

agh!!! I am struggling...my little girl is five and she is having the hardest time being friendly to her peers...(i.e.- she will say " I'm not playing with you anymore" when some one doesnt do what she wants them to..ect..)
This part of parenting is really starting to get to me...I dont know what it is..its not like she hasnt struggled in this area before, it just seems now more than ever... sometimes I just want to shelter her from all of her friends and not allow her to play with them
( what will that do?) I know in my sinful heart... I am embarrassed at times, and my expectations are high,then my fear is that no one is going to want to be around her because of her actions ( i know this is taking it a little to far, but its what I believe from time to time)
...I know the LORD is allowing this thorn in my flesh to be here to get rid of all of this and more..but my goodness... My hearts desire and prayer has been that she would be a Barnabus to all those that she comes in contact with and that she would have a heart that is full of kindness, mercy, and compassion

pray for me as I train and instruct her in righteousness
all and any ideas are welcomed
:)