Charl-x,
My pharmacist gave me a goal weight of 9st 8lb and I am 5ft 6in. I think 10st 10lb is the top end of BMI and so long as you are within normal range (ie 20-24.9) then most will allow you to continue if you want to and have stuck to it successfully.
I am in a bit of a blip at the mo, maintaining at 10st 5lb ish and I am happy enough but will be aiming for 9st 8lb by Xmas!