7 pounds of fat
No, you should be able to bench your weight at least.
According to the body mass index chart, a weight of 128 pounds for a person that is 4'8 is considered overweight. An ideal weight would be between 90-110 pounds.
21.25 pounds of fat
It depends on your body frame and the amount of muscle that you have. Weight is related to height and body composition rather than age. If you have small body frame then the average weight is about 140-148 pounds. If you have medium body frame then the average weight is about 145-157 pounds. If you have large body frame then the average weight is about 152-172 pounds.
Your body can change its weight as much as 6 pounds a day.
Based on the Body Mass Index, your ideal weight would be anywhere between 111 and 146 pounds.
100 pounds
Stone is an Imperial unit of weight generally used for body weight. It is equivilant to 14 pounds. Body weight is given in stone and pounds. 10 stone 8 pounds would be 148 pounds. Try this conversion chart: http://gwydir.demon.co.uk/jo/units/weight.htm
50 pounds
138 pounds is '9 stone 9 pounds' ; there are 14 pounds in one stone and height does not affect weight in stone. Height and weight are needed to calculate body mass index (BMI) which in this case would be around 23; or a healthy weight.
If you are talking about 60 pounds body weight, PLEASE CHECK WITH A MEDICAL PHYSICIAN - this may not be a healthy goal.
Everyone's weight is different. And so is their body. I understand why you would want to know but everyone's body is unique, and it doesn't matter what you way unless you're weight is harmful to you're body. Which would mean you were over weight by at least 100 pounds