Twenty-seven-year-old Tenille Nichols and her seven-year-old son and 10-month old baby daughter left a home in Coombabah on Tuesday morning to drive to the Sunshine Coast, police said.

Ms Nichols hasn't been heard from since.

Family and friends say the lack of contact is out of character, with police saying they "hold serious concerns" for Ms Nichols and her children's safety and wellbeing.

Ms Nichols was driving a 2012 silver Nissal Dualis station wagon with Queensland registration plates 6060 XHP.

Australian Associated Press