Chris...

How old? When I got her from the shelter last December one record read 3 years old and her vaccination record read 18 months. Further enquires revealed that when she first arrived at the shelter in May last year the manager estimated 3 years. On her visit to the vet in August he estimated her at 18 months. So, as no-one really knows I have decided she is......
When all else fails...take the average and divide by two!