My dd just turned 7 months and is 13 pounds (off the chart according to my doc). These charts are very old, there are new ones for babies that are bf. If she is gaining, is healthy and happy, I wouldn't fret about the weight. You don't want food to turn into a fight with her, she may end up with eating problems when she's older as far too many females have. I remember when I was a child I was very skinny and my mom always tried to get me to eat- even made special dinners for me that were different from the rest of the family, I was still fussy and my twin sister would clean my plate for me to prevent the food battles in the house. She ended up with a weight problem and has been obsessive about her weight and food her whole life. Just try to ensure she's eating healthy, as pp suggested- yogurt and avocado are great choices, banana is higher in cals as well.
In terms of sweating, she's probably an active lo, just make sure she's getting enought fluids so that she doesn't get dehydrated.