Gossip that has gone very wrong

[ChorltonCreamery]

One of my children is in an 'organisation' think church group, Scouts etc They are in a friendship group of about six or eight and the mothers are friendly enough, if some of them don't know each other they will have mutual friends etc.
One of the women 'A' is a real character, very funny and charismatic with very talented and charming children. When one of her children came to my child's birthday party I thought that her grandfather had brought her...it was their father. A is married to a man old enough to be her father. He has grandchildren who are older than his children with A.
At the weekend the mothers went out together for the first time but 'A' couldn't come. The conversation turned to 'A' and the relationship that she had with this man. At no point was it 'nasty' as such but comments were made about the age gap etc. One parent admitted that the family had not been invited to a gathering at a school friend's house because the husband had found it weird to have to talk to someone old enough to be his dad.
Well last night in front of some of the children 'A' confronted us! She had been briefed (I think by a woman at the next table to us who had lingered after her bill came). She completely demolished us intellectually, asking what had she done to provoke such a reaction and picked on us individually. Unforgivably she then asked a teenager whether her mother had brought her up to behave so despicably a manner and whether she thought it was appropriate to gossip behind people's backs. One of the group disappeared round a corner and was sick.
It was utterly hideous. I know I am guilty of joining in. I don't know what to do. One of the other children has told my child what happened. Only one of the group has responded to my text saying that she thinks that 'the circle' is at an end and the other person that she has spoken to has spent the morning in bed with a migraine.
I know I am to blame for joining in but I didn't initiate the gossip, but how would you react now. What is the way forward?

[BloodyHellBeryl]

"you wasn't" is an example of dreadful and wrong grammar.

You do realise that the posters native language isn't English?

I have a lot of experience having worked following two post graduate qualifications in Psychology, one from the Institute of Neurology and I worked at the Institute of Psychiatry.

Have you considered asking the poster about her career? I think you would be shocked.
@Ellyess.

[StillCoughingandLaughing]

Also, if we’re going to get into critiques of language use, dreadful grammar is wrong by implication. There’s no such thing as dreadful grammar that’s right.

[gruffaloschildgonewild]

Seems like OP is not gonna tell the whole back story. My guess is that the teenager might have said something to A's kids about the age gap between the parents. A might have mentioned it to the other friend who then might have told her how OP and her friends were discussing them behind her back. Hence A's anger towards all of them.