My DD (Y6) has been having a few issues with her friendship group at school recently, started last term and continued into the new school year. Things were especially bad at the start of the new school year with this child F being really awful to DD, culminating in an incident where F physically attacked DD at school. We called a meeting with the head, who was excellent and called in F's parents as well. DD and F have a mutual friend, O. O is a bit of a sheep and although the two of them get on really well most of the time, if F is around O can be fairly horrid to DD as well.
Things seemed to calm down over the last few weeks and DD and F were tolerating each other (it's a small school so hard to avoid). We spent some time with O and family over half term, all was well and we had chatted about the issues DD was having with F. Last week DD was planning to go trick or treating around the local (very safe, small village) estate with a group from their class (including O and F) and they had talked about it in school and F had told DD that she wasn't allowed to go with them. I had already loosely discussed the plans for taking the kids trick or treating with O's mum (both have younger siblings) and when DD told me what F had said I messaged O's mum to say that F was being problematic again so DD wasn't going to go with their group as I didn't want anything to happen whilst they were excited, in the dark and full of sugar.
O's mum phoned me, assured me that there were no plans for F to be part of the group, she hadn't heard anything from F's parents about meeting up and as far as she was concerned F wasn't involved, it wasn't anything to do with F and we were going out in a group with our DD's, their siblings and another classmate G and that O's dad was going to stay with the group the whole time anyway at the request of G's parents.
Halloween came and went, lo and behold F was there and although O's dad was with the group at one point, I bumped into him later with my other two DD's (smaller and much slower!) and he had lost track of the group. Anyway, they all turned up, ended up going to back to another classmate's house for a bit then came home. I had several messages and calls from O's dad to say where DD was and when he was leaving to come home etc and saw them several times as we all looped around the estate. No-one mentioned how it was that F came to be there (F doesn't live in our village).
Having spoken to DD afterwards, it turns out that F went back to O's house after school, had tea and then went out with the group. I'm irked that despite all her assertions several days earlier that F wasn't going to be there O's mum then made arrangements to have F after school so they could all go trick or treating together. I can't believe she didn't tell me. I suspect DD knew F was going due to it being discussed at school but why would O's mum go to the effort of ringing me to say that F wasn't going and then make arrangements for F to go and not bloody tell me? O and F do get on well and F usually goes to O's about once a week after school so I suspect O's mum doesn't see F with quite the same view as I do and possibly thinks I'm over-reacting (I'm not, DD isn't the only child F is vile to). But I do feel that she deliberately concealed from me the fact that F was going to her house and then out with the group and thought it would be ok because her DH was going with them.
O's parents are good friends and DD and O are likely to be the only two children from their class going to the same secondary school a train ride away in the next town. I'm not worried about F as such as once they've got through this year DD is unlikely to see her again very often but I do feel troubled by O's mum's "deception". That's way too harsh a word but I can't think of a better one, she knew how worried how I was, assured me that F wasn't invited and didn't tell me when she was! I don't really want to step back from the friendship as we do live in a small village and it would be hard but I don't know how to reconcile this in my head for the future. Does anyone have any advice please? Sorry this is long, I didn't want to drip feed.