Friends with another mum but their child is naughty

Also want to add that me and this mum aren’t super close friends. We’ve known each other for a year and message now and again and meet for the odd coffee

I think it depends on how the other mum deals with the situation at the time. If she’s genuinely trying to teach him and taking action to help him understand how to treat others, then I’m sure it could just be a phase. But if she’s not really addressing it or helping him understand, I’d probably personally start to back away a little.
You can’t change how other people parent, but if it’s affecting your daughter and nothing seems to be changing, she doesn’t deserve to keep putting up with it either. All you can really do is keep showing your daughter how to share and be kind, even in front of him. As she gets older, she’ll learn for herself who she enjoys playing with based on how they treat her, and vice versa. That’s just my opinion though xx

I feel like this is such a common experience and there’s no real “best” way to handle things... I’m dealing with something similar except the naughty child is my nephew (also 3), his mom is my sister. So I have the ability to step in with Auntie authority at times when he isn’t following rules, especially if they’re at my house. I’ve talked to her about different parenting techniques and how to teach him sharing, house rules, etc.

But in your case since you aren’t very close with them, I’d probably open that door by asking basic parenting questions.
“how do you feel (child)’s socialization is going?”
See what her answer is… she might feel comfortable admitting that she’s not sure what to do with him sometimes and feels bad about it.
Then talk about different ways to try to help him learn the skill of sharing. He has to learn it from someone.

I’d reframe it. My child behaves like this. It’s not for a lack of decent parenting on my end or that my child is bad or misbehaving, it’s that my child is shy/socially anxious and doesn’t know a better way of dealing with (despite me giving her the knowledge and practice). When other kids are like this with my daughter, I just explain it from that perspective because unless the parent really is crap, it’s more likely just normal toddler behaviour.