I haven't read this whole thread so forgive me if I'm repeating what someone.else said.

I would think it's common sense that my DS would be invited to a 1y.os party. But would most likely reference the fact I would bring him, casually. Eg- "Ooh, DSs first party invite!" Honestly, I think it is rude to invite other peoples children but to exclude hers. I would be offended., even if my DS was a pain in the butt and it was warranted. Consider how you would feel if everyone elses kids were welcome but not yours. That'd hurt. JMO.

I don't think there is a tactful way to say something hurtful such as this. Either lose a friend, or put up with her kids. Sorry to be blunt, just how I see it.