Missouri investigators are trying to solve the mysterious deaths of a 2-year-old girl and her 7-week-old sister as the girls’ mother sits in jail, charged with assaulting her husband hours before the children were found dead.

Ireland Autumn Jane Ribando and her baby sister, Goodknight Berretta June Ribando, were found unresponsive at their home near Kearney Wednesday afternoon, according to FOX4 in Kansas City. The news station reported that the girls' mother, Jenna Madelyn Boedecker, told police she went outside and found her children not breathing.

Boedecker told detectives she picked the girls up and ran with them to a neighbor’s house for help.

Officials with the Clay County Sheriff's Office reported that deputies and paramedics from the Kearney Fire Protection District arrived at the family's home around 12:10 p.m. Both children were pronounced dead at the scene.

The Kansas City Star reported that deputies contacted the girls' father about four hours after they were pronounced dead to inform him of their deaths. At that time, the man, identified in Missouri court records as Joseph A. Ribando Jr., told them about a fight he and Boedecker had the night before.

The couple argued around 11 p.m. over Ribando's fidelity, the Star reported. He told investigators that, as he drove away in his truck, Boedecker threw a brick at the vehicle and then rammed it with her Jeep.

Ribando stayed overnight at his mother's house, where he was notified the next day about his daughters' deaths, the Star reported.

According to family members, the girls have a 9-year-old sister who was not home when they died.

Boedecker was booked Wednesday on charges of assault, third-degree domestic assault, armed criminal action and first-degree damage to property, Clay County Jail records show. She remained in jail Friday.

A Star reporter questioned whether Boedecker was a suspect in her daughters’ deaths.

"The only thing I'm comfortable saying is she's charged with assault," Clay County Deputy Jon Bazzano told the newspaper. "And it's too early for me to put labels on something when we're trying to determine exactly what happened."

No cause of death for the children had been determined as of Thursday, and investigators were awaiting the results of autopsies performed by at the Jackson County Medical Examiner's Office, Sheriff's Office officials said.

Investigators told FOX4 that there was no evidence of trauma on either of the girls' bodies. They did not appear to have been struck by a car or shot, and there were no signs that they had drowned.

Reporters with the news station spotted an SUV with its doors open on the family's property and questioned whether the children's deaths could have taken place inside a hot vehicle, FOX4 reported. Investigators said that was something the medical examiner would have to determine at autopsy.

So far everyone that’s involved is working with investigators,” Clay County sheriff’s Capt. Will Akin told the news station. “There’s no reason to believe anyone is trying to hide anything, but we know with other situations, we want to make sure no one is lying and make sure we get to the bottom of this.”

Teresa Bailey, the girls’ paternal grandmother, said she was preparing for a Fourth of July party when deputies came to her home with the devastating news of her granddaughters’ deaths.

"I cannot believe it," Bailey told FOX4. "We are all in shock and disbelief that these two beautiful little girls are gone."

Bailey said Goodknight, who was born on Mother’s Day, was just starting to lift her head and show a keen awareness of her surroundings. She described Ireland as a joy, full of life and smart.

"She was 2 years old and could hold a conversation like a 4-year-old," Bailey told the news station. "She was amazing. I called her a star child."

One of the only things she has left of the little girl is her laughter, recorded as a ringtone on Bailey’s cellphone.

“I was babysitting her, and I got her laughing like that, so I recorded it,” Bailey said.

She offered a word of advice to other parents and grandparents.

"People should hold tight to their kids, take care of them and love them, because you only got one shot," Bailey told FOX4.

A family friend established a GoFundMe page to help pay for the girls' funeral.

"I couldn't imagine being in Joe's shoes right now," Randy Pogue wrote on the fundraising page. "Any and all donations received will be provided to the family for funeral expenses. Anything you can donate will be appreciated and allow the family to focus on healing during this tragic time and not stress about paying for a service."

As of noon Friday, the page had raised more than $7,000 of its $20,000 goal.