I think any person (or in this case fictional character) goes way too far when their actions are very likely going to wind up hurting their children more than anyone else. Sami used her children and didn't consider the effect on them when she hatched this revenge plan or when she made them part of her sham wedding. They will be hurt if their father goes to prison. They will be hurt when they find out about Abigail (who they love) and their father. They will be hurt when they find out what their mother did to their father. They will be hurt if they hear other people talking about what a pitiful excuse they have for parents. They will be hurt if their Nono retaliates against their mother. There's no end to the many ways the children can be hurt. Is there any way possible she thinks they can be shielded from this?
Sami to me has always been classless and a little trashy
OT: I have the same opinion of Eve and even think the two look/act very similarly.
EJ is the same person he has been throughout the 8 years they've known one another. She didn't buy a pig in a poke - knew what she was getting despite her mostly insincere "he's changed" mantra. Sure she was angry for a minute after all the crimes he's committed against her family and the people of Salem, but no one ever forced her to go back to him after Johnny went missing.
It's egoism in the extreme for her to react this way, this time, when she reacted less than appropriately to much worse actions/crimes committed by EJ. Sometimes you just need to admit your mistakes and move on. Revenge might feel good in the short term, but when you hurt other people it goes too far.
PS: Personally, I'd pull a Stefano-Bernardi (sounds like a drink) on EJ and leave it at that. Abby is a younger stupid version of Sami when it comes to men and they should actually bond over what a female dog EJ is.