It's an 'Imperial' measure of weight 2st = 2 stone. 2 stone = 28 pounds weight 28 pounds = 12.7005 kg In UK, USA and probably other places too, the amount of weight you lose or gain is almost always quoted in pounds and ounces. 16 ounces = 1 pound 14 pounds = 1 stone

2=second, st=stage. In a competition, it is divided into stages. She admits that she was lost at the second stage in the competition. The simplified writting for the second stage is 2st.

2 st = 2stones. It means that she lost 2 stones in weight. I am not sure how many kgs that would be. I think it's 12.6kgs that she lost.

Yes! I think Neal is right. She admit to having lost weight.

Yes, "twice", "two times" seems to fit best. "2 pc." (pieces)? Keeping "2" and "st" I thought about "21st". That would mean she would have lost this year's competition (/race), being number (/rank) 21. Or that this key is the 21st she lost this year? (I know someone who may be in such a situation from time to time...)