Hi my name is maria lily, and I'm trying to gain weight!
I'm trying to gain 5 to 10 pounds in at least a week. Is that possible?
Or at least see a difference in my weight in a week?

Gaining more than 4 or 5 pounds in a week is dangerous, especially for someone small. Try to gain more like 1 or 2 pounds a week to be safer. What you should do is increase your caloric intake, but not in junk, try to eat regular foods. Also, you can exercise ( I know this sounds weird, but trust me) to increase muscle mass (which weighs more than body fat).

Possible, but I agree with charlotte234s, also dangerous. You might be interested in ensure plus. They're designed to help people maintain a healthy weight and I know they can help you gain weight too because my grandma started drinking them and she gained a few pounds