Really awkward situation and I'm stuck in the middle

[OooIcouldCrushAGrape]

Hi advice please
Ok, so school pick ups. I have a group of mums I stand with. We have become good friends. Chat in playground as you do and sometimes meet up outside of school
Another mum has started to join group, we are usually very welcoming. I won't go into detail as too outing but she is irritating to say the least. However, I'll talk to most ppl and lend an ear but the rest of the group are starting to get bitchy about her, turning their back on her and making comments that are obv aimed at her so she can hear. When I talk to her they say why u talking to her!
I've told them I'm not going to be rude to her
I don't know what to do. I don't want to fall out with anyone. But I can see this situation getting more awkward and nasty and I feel bad for the mum. What can I do?

Yeah, I get they said it to you, but I wondered if it was when you were talking to her. At least they said it afterwards I suppose.

they still sound like 12 year olds.

what's actually 'wrong' with this woman??

Depends on how irritating she is Do you want to talk to her or just feel you have to? I never had this at my dcs school everyone exchanged pleasantries in the playground, obviously there were some friendship groups but they wouldn't ignore anyone.