Are they being deliberately unfriendly?

It does seem very odd. Perhaps it is members only and they only added you to the Facebook page because they thought you'd be passively interested.

I would imagine someone within the group complained and put them in a difficult situation Someone probably said well if we all brought family and friends blah blah blah

I think that's wise, starbox. It sounds like one of those situations where you're just baffled. So shrug and move on. ?

No, theyre perfectly pleasant about it. And granddaughter really was good (and I'm not a doting grandma whose kids can do no wrong!) There's no facilities (a gazebo in a field). I think we'll just keep our distance!

Sorry. A lot of questions. It's just a rather weird story.

Were they being deliberately friendly before? Or are they generally casual?

You stress how good your four year old granddaughter was. Is it possible that they disagree with your assessment on that?

I think I would unjoin myself from their Facebook page. Perhaps they just want you to know they are the centre of attention with their little group. Leave them to it.

It sounds like they are the ones being unreasonable but I would ask for a reason. Maybe the facilities don't cater for too many people and they have to give priority to members only?

I wouldn't get upset about it. It's probably not worth worrying about.