Sorry DD,
If you are entertaining letting her come back, you are already back to zero. Nothing has changed since the FIRST time you caught her ( emphasis on FIRST because you have no idea whether she was cheating on you before that). She wouldn't quit her job then, she won't quit her job now. She tells you she is NC with the OM. Big deal, she slept with him got pregnant, aborted the poor child, and now tells you she wants to work on the marriage. You can lie to yourself about not divorcing for the sake of the kids. The fact is for all the time she spends there, and what she does around the house and for them, they would adjust easily to her being gone. She is never there any ways. You have to at least be truthful to yourself. At this point your self esteem is so low, that you think all you deserve is her. WRONG. You don't deserve her at all. You can't deny that you letting her off time and again only reinforces her bad behavior. She has no respect for you, and knows that if she just lies again and says she wants to work on the marriage and that she won't see the OM (and it is a lie. Because if its not him it will be another man) that you will take her back. If you had a friend in the same position as you, you would shake him and tell him to get real. That is what I am trying to do with this post.
The example you give to your children here is so destructive and if not changed increases there chance of searching our and finding a woman just like there mom. Boys marry women like their mothers. So instead of putting a stop to this now. You entertain reinforcing there education in accepting a life as a cuckold. DO YOU WANT YOUR CHILDREN TO HAVE SELF ESTEEM LIKE YOU? DO YOU WANT TO SENTENCE THEM TO THE LIFE YOU LIVE? Each time you give in. You tell them "Hey kids, this is how a marriage works. Your wife will cheat on you, you will be depressed and sorrowful your whole married life. Isn't this wonderful"
There is more at stake here then the pain you are feeling. There are your sons future happiness. Please reconsider even entertaining the thought of not divorcing her. I know this is harsh, and it hurts to read it. But DAMN man, you have only one life and your children have only one life. Don't do this to yourself or them.