It seems from the intrepid set reporters today that Amy is in fact a policewoman (seen filming in said uniform with the Eleventh Doctor wearing 10's outfit (sans jacket), indicating the first episode.)
They also report a snatch of dialogue with Amy saying to the Doctor: "Twelve years of therapy!" That supports the idea that the Doctor first meets her as a child and then later as an adult.
They also report a snatch of dialogue with Amy saying to the Doctor: "Twelve years of therapy!" That supports the idea that the Doctor first meets her as a child and then later as an adult.