DD has a middle name which we've ended up calling her on a day to day basis.
She has a lovely first name which is quite long and that we still completely love! But we call her by her middle name.
Is it worth getting her name legally changed so her middle name is her first name on her birth certificate/legal documents? 
She hasn't started school yet - would it be possible to put her middle name as her first name on the register etc?
Thanks 