Her parents Kate Barlow, 34, who was driving, and John Paul McGrady, 39, escaped without serious injury and kept a vigil at her bedside. But they had to explain to Megan when she woke up that her big sister Sadie, six, had died in the crash.
Megan and Sadie were said to be 'inseparable'. Sadie died at the scene of the crash and 'critically injured' Megan was air-lifted to Alder Hey Children's Hospital in Liverpool.
The girls' grandfather John McGrady, 62, said: "It is heartbreaking - the two girls were inseparable. They were always together in the house or if they went out together. Always together, always playing.
"I have spoken to John Paul. Megan woke last night and cried, asking for her sister. She is sitting up in bed now - I think they have explained to her.
"Sadie's gone but Megan is still there, she will be in hospital for a few more days but she will pull through. Sadie was a beautiful girl. She was never in moods or anything like that - always happy.
"Sadie enjoyed school, she enjoyed herself. It's hit everybody, it's such a shock. I haven't been out. I used to go out every day, but I just can't face people in the street, it's just too hard."
Seven people were injured in the two car crash on the A548 in the village of Gwespyr, North Wales, including two of Sadie and Megan's cousins.
Sadie attended Bryn Pennant school. Assistant headteacher Julie Davies said: "Sadie was a bright and confident child with her whole life ahead of her.
"She was popular and well-loved by pupils and staff. She would greet visitors with a beautiful smile and a friendly comment and loved lengthy chats with her teachers. She was kind, sensitive, thoughtful and wise beyond her years, a real character who was adored by everyone.
"For her to be so cruelly snatched at such a young age is absolutely devastating. We cannot begin to imagine the distress that her poor parents and family are experiencing. Our hearts ache for them in their suffering. This has had a tremendous effect on the whole community."
Mostyn councillor Patrick Heesom said: "The whole community is distraught. Sadie was a little angel and this is completely devastating. Sadie was a darling - she could often be seen playing with her sister and friends. This is heartbreaking and my thoughts and prayers are with her parents and the rest of the family."
What a heart-breaking story. We wish the family all the very best.