The wacko woman who allegedly snatched a 4-year-old boy away from his grandmother outside a Brooklyn McDonald’s on Monday has been busted for the heinous act, according to police.

Chrissy Payne, 47, of Flatlands, was handcuffed around 11:45 p.m. Friday — days after she allegedly yanked J’Marke Roberts from his 66-year-old grandma outside the fast-food joint on Eastern Parkway near Utica Avenue in Crown Heights, authorities said.

The brazen suspect tried crossing the street with the boy before his off-duty cop mom, Anyia James Roberts, grabbed him back, sources told The Post.

Payne was hit with charges of attempted kidnapping and endangering the welfare of a child.

The suspect then fled empty-handed, and no injuries were reported, police said.

J’Marke’s father and Anyia’s husband, Gentle Roberts, boasted that his wife — who is 7 months pregnant — is a hero after the horrific attempted kidnapping.

“His mom pulled him away from her,” Roberts said adding that, “she’s a strong woman. She’s back at work today.”

Gentle recalled Anyia standing her ground when Payne allegedly created a harrowing tug-of-war with his wife and mother in law.

“She was saying, ‘That’s my kid!’ She was saying that more than once,” Roberts told The Post.

“The lady grabbed him by his shirt on his shoulder, and she wouldn’t let go. She was fighting his grandmother. They were pulling him back and forth, and he started crying.”

After the ordeal, J’Marke, despite being shaken, was back at school on Thursday.