Brisbane's new children's hospital is not diverting seriously ill children to other facilities, says the head of Children's Health Queensland.

The governing body for the new children's hospital in Brisbane has denied a report that sick children are being turned away because of a lack of beds.

The Sunday Mail reports that seriously ill children are being diverted from the Lady Cilento hospital and surgery cancelled amid a shortage of beds and staff.

However the chief executive of Children's Health Queensland Hospital and Health Service, Fionnagh Dougan, says while elective surgery is occasionally rescheduled, no seriously ill children have been turned away.

"The Lady Cilento Children's Hospital (LCCH) is not full and has capacity to admit any child requiring tertiary-level in-patient care," Ms Dougan said in a statement on Sunday.

"The LCCH has never turned away a seriously ill or injured child requiring emergency care.

"There is no instance of or plans to transfer a child interstate for emergency surgery."

The Sunday Mail article refers to a hospital director's email to staff that reportedly says the facility is at "absolute capacity" and foreshadows the cancellation of major surgery.

Ms Dougan said there had been more patients than usual in recent weeks and the hospital's pediatric intensive care unit could increase its average capacity as required.

It is standard practice to transfer children to other hospitals to ensure intensive care beds remain available at Lady Cilento, she said.

Queensland Nurses Union secretary Beth Mohle said she is aware the hospital is 30 to 40 theatre nurses short of what is required and existing staff are working excessive overtime.

"I'm not aware of any particular examples of children being turned away, but it wouldn't surprise me if that is occurring if they haven't got sufficient staffing to safely care for children," Ms Mohle said.

Staffing shortages has been a problem since the transition to Lady Cilento from Brisbane's previous children's hospitals, the Royal and the Mater, she said.