Welcome to SR.....I'm so sorry for the situation that has caused you to seek this forum out.
Addicts are responsible for their actions. Addiction isn't an excuse for bad behaviors but it certainly may be a reason. There is no reason to rush into any decision. Her actions will be very telling now that the information about her affair and addiction is out there.
Please take care of you, your finances, and your precious children. And know that you have a resource for support here.
gentle hugs
ke