A bear called Blue

Harriet never goes anywhere without her beloved bear Blue, so when they become separated he knows that Harriet must be searching for him. Blue might be lost, but he never loses hope. Days, months and years pass, until one day Blue finds himself on a stall at a summer fete. He catches sight of a little girl who looks just like Harriet, but it can't be, wouldn't she be grown up by now? And why does the little girl's mum look so familiar to him?