Does it hurt to feed too large??

I have loads of conflicting advice. The guy I bought my bp from advised me to feed up my little 10 month old as best as I can. He said on food size, if she takes it then feed as big as possible. So he sold me a large mouse and I tried to feed her on it tonight after she normally takes medium mice. She had problems because the mouse wasn't warm enough. When I heated it up with a hairdryer she sniffed it but didn't realise it was food. So I put her hide in her feeding box and dangled the mouse. It wasn't until i held the mouse stil that she actually bit it and wrapped it, although with not much strength. It took her forever to work out how to start swallowing it, I adjusted the position of the head slightly to help her. She took about 15 mins to swallow it then, it looked like a mighty stretch though! Is it possible it could do her any harm? I heard a few tiny cracking noises as she swallowed it! I can see the mouse inside her in her belly. I'm not sure if the food is supposed to be 1.5 times the width of her head or her belly, but the mouse is like 2.5 times the size of her head but 1.5 times width of her belly but she managed it! And how long should I leave her til I feed her again after such a large meal? She was looking underweight so I wanted to give her a good feed. Have I done the right thing an is it normal? Help please!

Bigger is not better, not only it can be dangerous if you feed live but it can also lead to regurgitation.

BP in captivity are generally overfed and can do just fine on a prey equal their girth size once a week (for hatchlings and juveniles), of course their are still people out there that are old school and feed the biggest prey they can find even to adults.

If you want a BP that eats with consistency feed smaller prey weekly, there is not need for your BP to struggle when eating or be sluggish for days after a meal.

Relax, everything is fine. They can take a lot bigger prey than you would expect without harm. However, if you want your snake to eat consistently, feed appropriate sized prey about the same girth as the snake. They sometimes go off feed if they ate too big.

As mentioned, they can go off feed if you go too large. Here is a real life example:

Snake A and B are the same size

Snake A eats a 150g rat, goes off feed for 2 months and consumes 150g in 2 months

Snake B eats a 75g rat every week for 2 months and consumes 600g in 2 months

Snake A is no longer the same size as snake B

I used to feed slightly larger than the thickest part of the body, but after 3 regurgitation's in the past few months I've changed that. Now the largest prey I feed would be a small sized rat and thats to my 2000g+ girls too.

Feeding too large of a meal can also lead to a prolapse, not just in ball pythons but in any snake. If yours recently had the big meal make sure she stays very humid and has plenty of fresh water so she stays hydrated, which helps reduce the risk.

Do you know how much yours weighs? I have some ten month old BP's that would snatch up a large mouse and look for seconds, and that's with offerinng a rat weanling every 7-10 days, where most people would still be feeding them every 5-7 days since they're under a year old. They're in good weight also, so it sounds like yours may have been underfed a bit, but trying to pack on the weight and catch up in a short time isn't good for them, slow and steady wins the race with these guys.