The book opened with a woman panicking, trying to get home late at night. She's been on a date (i think) and left her two kids home alone. She falls and bangs her head, losing her memory. She spends the whole book in hospital, frustrated because she can't remember where she should be or who she is.
Her two kids- a tough, resourceful girl and a little brother are too worried to tell anyone that their mom hasn't returned home, in case the authorities get involved. They spend the book trying to cope alone with little money or food.
Towards the end the girl is very focused on a school trip to Eastbourne (I think), because it's close to where her mother was going out on the night she disappeared. She hatches a plan to escape during the school trip and go and find her mother.
I think there is a perilous situation with the incoming tide at Eastbourne at the end, but I might have imagined it...
HELP ME 🙏🏻🙏🏻