With your W's history, I would completely steer clear of her and any invitations. Something like this would be potentially appropriate if she had apologized, shown remorse and humility, with a change in her actions and character. Right now, this is a temp check and don't fall for crumbs.
Over time, if you can develop a good co-parenting R with her for your son's sake, that's great. But she would need to put in a lot of work for that.
