The mother of the boy who died after allegedly being forced by his NYPD cop dad to sleep in a freezing garage took to Twitter for the first time since the tragedy, posting pictures of her kids in happier times.

Justyna Zubko-Valva, 36 — who told The Post she “unlawfully” lost custody of 8-year-old Thomas Valva and his two brothers to NYPD cop Michael Valva in 2017 — thanked the public for an outpouring of condolences in a message posted to her account around 2 a.m. Saturday.

“I want to personally thank each one of you for love and support towards me and my children. I am still extremely heartbroken, and devastated over the cruel and tragic death of my little angel Thomas that could have been preventable. Please continue keeping us in your prayers,” she wrote on her Twitter account, titled StandAgainstChildAbuse.

Thomas Valva died Jan. 17, after police responded to a report of a child who fell in the driveway of his family’s Center Moriches home. Dad Michael Valva, 40, and his fiancee, Angela Pollina, 42, were arrested Friday in the boy’s death.

Zubko-Vala followed with five separate posts of Thomas alone and with his 6- and 10-year-old brothers.

In one image, Zubko-Valva is seen kissing Thomas.

In others, the little boy is pictured flashing a smile while sitting on a playground slide and wrapped in embraces with his brothers on the beach and in a living room.

“Rest peacefully in heaven my sweet little angel,” Zubko-Valva captioned the gut-wrenching collage.

The mom had alleged for years that her children were being abused, using the Twitter account she started in 2018 as a platform.

She posted a series of videos appearing to show her sons denouncing their mom — what Zubko-Valva claimed was a result of her ex-husband’s and his second wife’s “brainwashing.”

“Daddy said to me that I can’t listen to you and can’t hug you . . . I don’t know why,” one of her sons said in a video shared in January 2018.

“Father and his girlfriend are brainwashing my special needs children and teaching them hatred towards their mommy. Parental alienation = children abuse. My children have a right to love their mommy. Taking away that right is a crime. #parentalienation #childrenrights #abuse,” Zubko-Valva Tweeted the following day.

Thomas’ brothers were reunited with Zubko-Valva Friday following the arrest of their father and Pollina.

Investigators believe Thomas and his older brother, Anthony, were denied food and exposed to “extremely frigid temperatures” as punishments while living with Valva and Pollina on Long Island.

Thomas died Jan. 17 of hypothermia after he was exiled to a “freezing” unfinished garage at the couple’s Bittersweet Lane home the night before, when temperatures were in the teens, according to police.