That first girl looks really thin to me. My girl is only 2000 grams and this is what she looked like at day 25-after prelay shed. Notice how thick and full she looks. She was so stretched from the eggs you could see her skin between her scales. Also, the protruding spine usually doesn't happen till closer to laying. In this picture you can see that it's starting to protrude, but didn't get really pronounced till a couple days before she laid.
Maybe it's just the angle of the picture, but to me she looks thin??? The second female looks lumpy, so maybe she's building. If you put an empty tub on the scale you can reset it to zero-all scales do this-then put her in to weigh her.