Keeping that assumption secret and continuing your lives

She was 15.

It's no morw fair than if OP has said he would willingly adopt the kids, only to later say he never actually did and assumed his wife would come to her senses

He would have been 17 if he'd said that

His wife is calloused and controlling, and a horrible partner. She lied about something that will dictictate the rest of their lives

She accepted something she didn't truly want at 15.

What the hell is wrong with you people.

The lady's going out of her way to do something amazing here and you're out here calling her "calloused and controlling", when she's a freaking 20 year old going back on a promise she made to her boyfriend when they started dating and she was 15 so as to take care of children and family in dire need.