BLUE TONGUE SKINKS

I have assumed Mush would be turning 2 around November. I got him Valentine's Day 2014 and was told he was a few months old.
I've been referring to him as a boy all along but after it was suggested, I do think Mush might very well be a girl...I just was so sure because of his size, that he was a boy. Never found sperm plugs with either of mine though.
Recently, I changed the way I was feeding them because they just seemed to be hungrier, even though they are both very well fed looking...Mush, I'm sure you all would say is obese. But now I feed them smaller meals a couple times a week which seems to have them more satisfied.
To my question...in the last 2 months, Mush has shed 4 times. He hasn't shed that much for a long time! He also put on almost 200 grams since May - again, he has not put on that much weight so fast since his first year. Strangely though, he did not grow in length, as he's still the 28 inches he was in May.
Meanwhile, my other one Duma who is just over 1 year, grew much slower and I don't expect will be anywhere near Mush's size. He put on about 100 grams since May and sheds about once a month.
Do they go through last minute growth spurts, as Mushy is doing, around his age? Or does this have something to do with the new way that I'm feeding them? Isn't it odd that older Mushy would be shedding more than Duma?
Duma is on top, Mush is in the middle:

Weeelll.... whoever is pictured on the bottom... I think has changed more than just in weight....

Have you housed them, or kept them, together without someone watching them the whole time...? Any chance they've mated...?
Otherwise, it may just be the time of year. Especially females tend to eat more and put on weight this time of year --in preparation for mating/growing babies.
Reptiles generally don't go through growth spurts per se --they generally just grow according to how much they're fed and how much they eat.

Was thinking exactly what Susann said....could one possibility be gravid? When my girl was she shed three times in four months and she is five years old. Nice bearded dragon, too!

Lol, it's easier for me to have record of all 3 of their weights together like that. Thanks for the compliment on my bearded, she's a wonderful girl!

No mating yet, they're housed separately. I have introduced them to each other a few times while out of their cages, more to see if I'd get some (obvious) sign that one was a boy.
Duma would get very excited and curious about Mush. Mush seemed curious at first but the last time I tried it, seemed submissive and uncomfortable about Duma coming close. I couldn't tell if that was his way of telling Duma that she's a receptive female or...if he was feeling domineered. But he had one of his worried looks on his face and I figured I'll just wait until I'm really serious about getting to pair these 2 up next year and consult with you all about behavior signs to look for. Both are sweethearts and non-aggressive but even though Mush is the bigger one...he's such a gentle mush that if something went wrong, I know he'd be the one getting hurt.
I guess this year has been a learning experience watching my babies mature into adults. I've suddenly had to learn how to deal with the preteens with my son...I feel like it's the same thing with my skinks!