viv size; muscle tone

Just fed my motley female and while I handled her- moving her to her feeding bin- I noticed her muscle tone was way down. She felt kinda weak, like she had just layed. She did lay a clutch earlier this year.
The thing is that I just moved her into a 25q. sterilite. It is kind of small for her I think. She was previously in a 40g. that I got rid of. She seems a little cramped up in a 25q. I probably will get a 20g. for her soon but I want to know- Is this smaller habitat making her weak?

Well if she can't move around freely and has nothing to climb on etc she's not got any way to exercise. Does she tend to be quite active or is she a "lazy" snake. I have my juvenile snakes (seperate tubs, both under 2 feet) in 25q tubs and find it too small for them.

But it depends on how active your snake is as well. One of my snakes is super, super toned and muscly but the other one is on the slim side - not weak tho.?

Might she be about to go into shed? I notice that a couple of mine hold themselves differently if I handle them around a shed and do seem more relaxed than normal.

As for moving around, if you give them a new tank some will behave like new arrivals and be inclined to hide away and be less active while they get used to the new surroundings. Might be worth just letting her settle for a month to see if she improves, before switching to to yet another tank. Some of them don't much like bigger tanks and oddly do better in more enclosed surroundings.

As long as she can still move, is alert and can do things like lift up the first quarter of her body to look around, then there might not be a problem. I think in your place I'd just keep a careful eye on her and see what happens.