Muscle Tone in Hatchlings

This isn't really something I am worried about right now, but it's something I want some advice in case I need to worry about something later.

I have two snakes, both the same age, that are eating in the same schedule. I have noticed though, that while my male has great muscle tone and firm sides, the female does not. I don't think there is anything really wrong with her, but she definitely is less muscular and firm than he is.

Neither of them are very aggressive eaters, but I have ever had them refuse a meal. He strikes, and she just kinda nudges it with her nose. Neither of them constrict. He hangs on tightly when we hold him, and she doesn't really. Despite being almost the same weight, he seems a lot smaller than her.

I'm not sure if there is anything I really need to do at this point since she is still growing, but I might start getting her out more often to see that she gets a little more exercise. If anyone has any other thoughts, please share.

Other info:
They hatched 7/19/2011. I received them 11/09/2011 and the girl weighed 9.3 grams. Last night (2/8) she weighed 22.3 grams and is eating 2 extra small pinkies every 7 days. I slit the backs of the pinks and dust with reptile vitamins. (Here is my iherp page if you are interested: http://www.iherp.com/Khena)

If you would like any other info, please ask. Thanks for your time!

Hmmm... without pics it is hard to tell.

However, a few things:

• Snakes can be born out of the same clutch and grow vastly differently, needing different nutrition requirements.
• Some snakes are more active than others, thereby building more muscle tone and burning more calories.
• Some lazy snakes need to be taken out and 'exercised'. You didn't mention how often you handle your snakes, but exercise will build muscle tone.
• Corn snakes ideally have a 'loaf-of-bread' body shape... a little indent on their top, where the spine is... instead of being rounded on top which is an early sign of gaining too much weight.
• One larger food item is always better than two smaller food items.
• Someone will mention you don't need to use vitamin supplements. They may not need them, but it isn't going to hurt, right?

Exercise Ideas:

• Stair climbing
• Swimming (some snakes will HATE swimming.) (Be sure to cover your tub/sink overflow hole before putting a snake in there. They will get into those holes.)
• Dangling them by the lower portion of their body, forcing them to do a "snake sit-up" where they will pull their head back up to your hand.

Thank you for the info! I usually get her out about twice a week, but I am going to start getting her out on the nights I get the boy out as well. I also took some pictures tonight, so hopefully someone can tell me if I need to feed her differently (I think she looks ok, she's just a lot different from her 'brother'.). I am also planing on making a new food order in another week or two, so she won't be eating two pinkies much longer.