The mum in question is the mother of one of the 3 year olds at dd's preschool. I also know her son (putative bully in the making) from play group.
He has this tendency to hit / kick the younger siblings of his peers. For example last week he shoved dd's 21 month old brother and today I spotted him pushing and aiming a karate style kick at the 10 month old sister of one of the boys. His mum witnessed this too and said "Damien (not his real name -but rather apt in the circumstances), please don't do that" - in a soft modulated tone as if she was asking him not to pick his nose! (These incidents and many others like them have been observed at Play group and at Pre School)
It's a consensus view that (a) he is rough and aggressive and (b) she has bugger all idea of how to address it
Have found out that she is trying to register as a childminder. Am concerned that a small child will be bullied by Damien whilst being minded by his drippy mother and have a miserable time. Don't think any small child would be at serious risk but do think it would be an unpleasant experience for them.
Should I do anything???? Would feel hideously underhand etc reporting my concerns anonymously...but then, I wouldn't want to be the parent who unwittingly placed my small child in that environment...