A self-proclaimed "mommy blogger" has been arrested upstate — accused of shaking her boyfriend’s 2-year-old daughter until she passed out, and causing serious injuries that eventually led to the little girl's death, cops said.

Brianna Valenti, 26, of Grand Island, faces numerous charges for the vicious act, including reckless assault of a child.

The victim's father, Cody Fuller, told WKBW on Monday that doctors believe she had been shaken "almost to death" by Valenti on the afternoon of Sept. 10. The toddler died over the weekend as a result of her injuries.

Valenti had been looking after her that day — along with her own 5-year-old daughter — when the alleged assault unfolded, Fuller said.

She reportedly called him, saying his daughter had passed out and was having "trouble breathing." Paramedics were called and the little girl was rushed to John R. Oishei Children's Hospital with "injuries resulting in her being unresponsive," cops said.

She was admitted into the intensive care unit, and deputies with the Erie County Sheriff's Office were contacted by Erie County Child Protective Services soon after.

"CPS suspected she was a victim of child abuse," police officials said in a release.

On Sep. 11, authorities arrested Valenti and charged her. She was still being held Monday at the Erie County Holding Center on $150,000 bail. Cops wouldn’t say if she'd be hit with more charges following the death of Fuller’s daughter on Saturday.

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