If a woman lets a man she met a month ago discipline her son, is she dumb/naive?

In an effort to avoid confusion, we'll call the man and woman "Jack" and "Jill"…

Jill's son's father went AWOL before he was born, so he's totally out of the picture. When her son was 17, she met Jack who is a con artist trying to swindle her. Please note his so-called background before I continue:

Jack is a widower with two children. Their mother was killed in a car accident. He has two jobs – lawyer and college professor. But Jill and her son have never seen any pictures of his family, nor spoke to them on the phone. And he was home every day to drive her car to the bus stop to pick her up from work. As for his deceased wife, Jill fell for it hook, line, and sinker… One day when her son had mentioned to Jack that one of his classmates from high school was shot and killed, and that he didn't look like himself in the casket, due to the circumstances, Jill pulled him aside and said in a soft tone, "I don't think you should talk about death and funerals around Jack, since he lost his wife so brutally."

They met on the internet in late January, followed by introducing him to her son, and then him proposing to her (all of which occurred in February), as well as the fact that she gave him a key to the house. During that month and the time leading up to her son's high school graduation, the red flags were there:

1. Jack started speaking to her son in a militant manner as soon as the son said that he doesn't have a job, despite the fact that he's in school and about to graduate. Apparently, being busy with his education meant nothing to Jack, as he perceived the son as a spoiled brat who needs to get his act together. He even kicked Jill out of her own living room as soon as she approached them, "Could you step back out for a few minutes? I need to have a man-to-man with him." Like I said, she was brainwashed. So she just listened and let him talk down to her son. He even told her how to punish her son -- every Friday and Sunday night, change the password on the dating website he chats on, so that he can focus more on his schoolwork during the week. FYI, his graduation was practically two months away.

2. At the time, her son was clinically depressed, due to being bullied at school. Jack insisted that he accompany Jill and her son to his therapy session. Not only did he violate their privacy (a total stranger who is not immediate family is with them at psychologist), but he belittled her son, "This man has never had a job in his life," which made the son cry. The doctor just shrugged, "Well, he's only 17" and such. As usual, his mom just sat there. On their way back home, Jack (who was in the driver seat) while Jill was in passenger's, gave her son a "don't test me" look in the rearview mirror.

3. Jack told Jill and her son that he will be adopting him, and that his last name will legally be changed to his, as well as on his high school diploma. Jill didn't object, but instead insisted that her son tell the principal about the name change so he won't offend Jack, as if he'd be a rotten son if he kept their last name on his diploma. She acted that same way when Father's Day was approaching ("get him a card" and such), so he got Jack a card while having no emotional feelings for his future stepdad of three months.

4. As prom season approached, Jack took care of the expenses for Jill's son's tuxedo and limo. His date and two classmates didn't have to pay one red cent, except a tip for the driver. While they were at the house taking pictures, Jack had a few friends or clients/swindling victims at the house, and said, "Guess which one is my son." An obvious "pretend to be a loving father" ploy. I mean, they're not related and he only knew Jill and her son for three months. So what was the point of asking them to guess which one is his son?

Does Jill lack common sense, or is Jack just really good at his "job"? In her defense, she's NOT a neglectful mother, and she graduated college and had a great job. So the fact that she let this man be verbally nasty to her son, was obviously due to how he played mind games with her, as she typically would've gone postal if anyone hurt her son. But instead, she sadly had this "listen to your stepdad. it's for your own good" mentality. In hindsight, perhaps Jill's lack of companionship for 17 years might have played a role in being an easy target, as she raised her son singlehandedly and had a dry spell with the men – she has "needs" and doesn't want to be alone, thus too desperate to see through this bastard.