Are any of my ball pythons showing signs of being gravid?

[Quiet Tempest]

Hi, im new and ill say hi to everyone, i currently have 3 adult females 1200grams and up from the smallest to biggest, i have one with my young male, the thin female, she will rarely eat for me and the person i bought them from claims they were all paired with several morph males, 2 look like thats possible but the thin one looks more like she layed eggs recently, even though i dont know what that looks like, my male has sperm plugs and he isnt interested in her at all.

Welcome to the forum.

I would definitely separate these snakes to individual enclosures. The thin one really shouldn't be paired with any males until she is up to weight. 1200 grams may be doable for some females, but that one is truly in no condition to be bred. She's far too thin.

the two other females are in the same tank, 3ft by about 2ft by 2 ft high. i have a heat pad and a heat lamp on one side and the water bowl on the other, both females seem to like to lay together on the side under the shirt, where the light doesnt reach them and they rarely go in the heat, they only did when i had a box under the light for them to hide but then i never saw them lol

I would get rid of the heat lamp. Lamps zap moisture out of the air and lead to arid conditions. You really don't want the humidity levels dropping out in your enclosure because it will lead to dehydration and shed problems.

now, more details on one, the lighter female im not sure is going to be gravid because shes eating like crazy, shes eaten 3 medium rats, 1 large rat and 4 mice within the past week and is still open to more food. lets call her snake1

You're feeding way too much! You're lucky that poor snake hasn't regurgitated such a huge meal. Keep in mind that when a snake eats, there is a race between snake digestion and rodent decomposition. You don't want to stack the odds in favor of rotting meat in your snake's gut. I will say that pet shop employees seldom really know what they're talking about - more often than not, they're just looking to make a sale. That's not to say ALL pet shop employees are ignorant or only looking to make money for the store but so many are that you should question anything that they tell you and research the information for yourself. You'll find nearly anything you could want to know about keeping BPs right here.

the next snake, shes a dark color, much darker then the other two, and shes going into shed right now but her belly for some reason is a peachish pinkish color, and shes staying near her water bowl slightly, though she uses it as a bathroom more often then not. shes snake2

The belly coloration is normal when they're going into shed cycles. I'd still wager that she's staying on that side of the tank to avoid the heat lamp. What is the temperature (on the substrate) on the heated end of that tank?

the last, the thin one, snake3, the person told me that they were all off feed until about a week prior to selling them to me, so they are all eating now with me, i read online that they wont eat much if they are gravid so im wondering if they are at all, the thin one has an arched back and when i first got her she had a slight lump near her tail, and you can feel her bones, and the male she is with has no interest in her at all.

any words of advise?

Are you certain that number three is a female? In fact, are you certain that all three of these are correctly sexed?