roughly 78 lbs.
I weigh 58 pounds and I'm in sixth grade. MY height is 4' 6''. I think i'm way under average
Well, you should NOT weight that much. The average weight for a SIXTH GRADE GIrL is almost 90 pounds, so if you are in fifth grade you should probably weigh less than sixth grader.
There is no average weight. Some are larger others are smaller.
About 8 to 10 hours.
The average weight of a 4th grade girl depends on her height. See the related question, further down this page, for in-depth information about weight in relation to height.