Getting to know school mums/WhatsApp?

[macmacaroon]

My DD1 has started school (reception). Someone has set up a class Facebook page but only about half the class are on it and there's about one post every three weeks. Friends whose LOs go to other schools in the area all have class WhatsApp groups up and running and they have already had mums nights out etc. And regular communication. Everyone uses whatsapp these days but no one has taken the plunge to set one up. I am a real introvert (also socially anxious) so want to set one up but find it very difficult to do it. Also worry about stepping on toes of mum who set up the Facebook group. I guess the real issue is I feel a bit disappointed that there no sense of "group" like I hear about from friends at other schools. I also feel a bit on the outside of things esp as I don't get to the gate much as I work.

I think there are just different types of school.
Apart from on MN, I've never come across this idea that you form a social group and go out with people just because ou have dc in the same class at school.
I've seen 3 dc through 7 different schools between them and never come across it. I've asked my sister, and asked a couple of other friends, and some colleagues, (different schools all over the City) after reading about it on here, and no-one has ever come across the idea you go out with other people because your dc happen to be in the same class.
I have become friendly with some people that my dc have been friendly with for years. One friend said she really hit it off with a couple of Mums and they have formed a friendship as a group of three, in the same way you sometimes just meet your soulmate at any time of your life, but most people are just happy to be pleasant and friendly and go about their own lives.
Had Whatsapp or FB messenger been around when mine were little, I've have expected any class group to be about "Which day is dressing up day, I can't find the letter" type messages, not a social meet up group.