Kouri Richins, the Utah widow accused of killing her husband with a fentanyl overdose and then writing a children's book about grief, is being sued by her late husband's estate, new court filings show.

The lawsuit was filed on behalf of Eric Richins' living trust and estate on Tuesday, accusing Kouri of theft, wrongful death, misappropriation and fraud, among other crimes, and asks for over $13 million in damages, spelled out in 18 different claims.

Kouri is facing murder and drug charges, accused of poisoning Eric with an overdose of fentanyl given to him in a drink the night he died. She has not yet entered a plea in the case and remains in custody.

Earlier this month, Kouri sued Eric's estate to obtain proceeds from his business and their family home, according to court filings.

Richins "misappropriates Eric's likeness and identity" in the children's book on grief she authored in the wake of her husband's death, the lawsuit against Kouri says, and has shared no proceeds from its sales with the estate.

The estate claims Richins stole money from her husband's masonry company in an effort to stanch debts from her real estate business, KRR, according to the new filing. Outlined in several aspects of the lawsuit are details about Kouri allegedly taking money from Eric's business that was earmarked for taxes, fraudulently opening a secret $250,000 loan, and charging tens of thousands of dollars on her husband's credit card.

Additionally, the lawsuit alleges that over several years, Kouri obtained several secret insurance policies on Eric's life, totaling $1.5 million in coverage and naming herself as the sole beneficiary.

CNN has reached out to Kouri Richins' attorney for comment.

Eric, 39, was found dead at the foot of the couple's bed in March 2022. An autopsy and toxicology report showed he had about five times the lethal dosage of fentanyl in his system, according to a medical examiner.

Richins told investigators at the time that she brought her husband a Moscow Mule cocktail in the bedroom of their Kamas, Utah, home, then left to sleep with their son in his room and returned around 3 a.m. to find her husband lying on the floor cold to the touch.

Around a year to the day after her husband died, Richins published a children's book, "Are You With Me?" about navigating grief after the loss of a loved one.