Oh, the key! How many times have I played hunt the key before we can go out! Mum has not yet left her key in the lock but we've tried to anticipate that problem by all of us ( three siblings and next door neighbours) having keys for every door - front, back and patio! As she never uses the patio door we hope that we will always be able to get in! Please let me know how your mum gets on with the turn key as my mum is not very good at learning new things and I would worry about her spending hours looking anxiously for the key to lock the door!