The statement was made around 8 p.m. on Sunday night.
There is still much not known about their disappearance, but the statement they released said that Marsek and her two children were located in the Wisconsin Dells.
The statement goes on to say they were found safe and "relatively healthy." Though it is unclear what exactly that means, investigators said that all three are being checked out at a local hospital.
Marsek, 33, her 2-year-old daughter Chevelle and 4-month-old daughter Macenzie went missing a week ago Saturday, October 6. She was last seen leaving her parents' house in Wauconda.
There has been no activity on her cell phone or credit cards, leading police she had been the victim of foul play.
Marsek had recently filed for divorce and was planning to move back in with her parents.
In an order of protection filed by her estranged husband Dan Marsek after his family vanished, he alleged that his wife had disappeared before and kept the kids away from him.
Sunday night Dan Marsek spoke to ABC7 on the phone and was ecstatic that his family has been located safe and sound.
"Right now, my focus is getting my girls and my wife home," he said. "I'll be focusing on that right now, like I have been for the past few days."
The Lake County Sheriff's office says police in the Wisconsin Dells report that all this time Marsek was vacationing with her daughters.
More information on this developing story is expected on Monday.