I have babies that hatched in mid July and are pushing 200 grams...I'd say your baby is on the lighter side.
The little line of black is where the umbilical cord was attached. It's normal.
Soaking can be a sign of mites. What substrate do you have her on? I'd put her on plain white paper towels for a week or so...will make it easier to see any mites which will look like tiny pepper specks...soaking can also be a sign of too high temps...the upside down meal shouldn't matter.