This happened with my Dd's friend (let's call her Lucy). I wouldn't have a problem with it but she got so much special treatment and favouritism for stupid things. Her mum was friends with her Lucy's and my Dd's teacher and would always nip out for words with her about various things. The teacher would let Lucy skip lesson to go to the school office and borrow Vaseline from her mum. She would always reserve seats at the front of any school play for her and her friends. My Dd got second by a wide margin in a sports day but they awarded Lucy second because her mum was judging. My Dd got fourth instead. Lucy always got to do jobs (organising things at break with friends chosen by her mum). My Dd unintentionally hut Lucy by saying she wasn't ready to sing for the school play in a really nice text trying not to hurt her feelings and the teacher got really mad a my Dd because Lucy was crying. Gave my Dd a shit role because she got so nervous her teacher was going to judge her for apparently "blowing Lucy off" and ran off after one verse. Lucy's mum also had contact via Facebook with other teachers and was always telling them that "Lucy is working hard at this so can you do x activity so she can show you?"
Things like this really piss me off - but is it normal at schools?