I'm 12 and I only weigh 4 1/2 stone and I'm desperat to gain weight please help me!

Can you translate that to pounds?

Since your so young and have lots of growing still to do, just remember it's very important to eat healthy foods, and never miss a meal. Don't use fast food or junk food, to gain weight because they just have too much fats, trans and saturated in them. Good choice would be foods rice in Omega 3 fatty acids like tuna, salmon, flax and walnuts, But also eat plentyof Poulty, nuts, seeds, legumes, chickpeas, kidney beans, peanut butter, omeletes, whole grain cereals, rice and pasta, granola, bagels and cornbread.
When it come to veggies eat avacodos, olies, potatoes, peas, corn, squash.
Now fruits, try fruits like canned in syrup, dried fruits and fruit nectar drinks. Or you can try using protein powders as a supplement or nutritional supplements like Ensure or a Instant breakfast drink along with your normal breakfast. Try to remember to take multi vitamins and mineral every day.
use milk instead of water in cereals, soups, sauces. Mix cooked chop meat, wheat germ, nuts, beans, or cheeese in casseroles, pasta, salads, side dishes. Try to add 300-350 calories to your normal intake of calories everyday. Stay away from empy calories like soda and foods that have no real nutritional value.

can you translate that to pounds?

1 stone = 14 pounds :) so if it reads right 41 stone would be like over 500 pounds, so I'm not sure if this is correct?