Kerry's 13-month-old daughter Dylan-Jorge Rose escaped the crash, as she was with her mother and George at the time.
The accident reportedly occurred when the 34-year-old Atomic Kitten singer's nanny took Heidi for an unrelated emergency appointment at the hospital (after she was referred by her GP).
A source told The Sun newspaper: “The front of the car is smashed in. They could all have been seriously injured.
“It was traumatic.”
The nanny and Mollie, 13, Lilly-Sue, 12, Heidi, eight, and seven-year-old Max were checked over in A&E when they eventually arrived at hospital for Heidi's appointment.
Thankfully no one was injured.
However Kerry - who is currently married to her third husband George Kay - was understandably left severely shaken by the event.
The insider claimed: “Kerry is distraught and feels cursed.
“Every time her life appears to be running smoothly, something like this happens.”
While no one was injured, The Sun have added that Heidi was kept in hospital overnight due to her unrelated illness.
She reportedly had her mum by her bedside, as well as her dad - Kerry's ex Mark Croft.
The mum-of-five is yet to speak publicly about the incident and last tweeted a message yesterday afternoon which read: "Hey all... Sorry not been on for a while but been crazy busy! Will catch up with you all soon! Love ya stay happy."