New Boa Regurg/Vomit

[XSPWR]

So I just recently bought a Guyana BCC from an online seller. They unfortunately fed her either the day before shipping or the day of, because within 16 hours of getting here she regurgitated a very undigested mouse.

I waited exactly 2 weeks before feeding her again. The mouse I fed her was probably about 60% the size of the widest part of her body. She did great and kept it down no problem.

One week later (this last friday) I fed her the other mouse that came in the 2 pack with the first, same size. About 2 and a half days later I found that she had vomited up that mouse. It was pretty well digested, save for the tail.

I'm kinda at a loss as to what the cause may be here since she did fine with the first mouse I fed her... Her cold side surface temp is right at 80 degrees, the ambient is 83 and her warm side has a UTH that is set to 92 degrees (also has 2 layers ZooMed EcoCarpet, so after laying on it a bit it warms up to around 90, but surface reads in the high 80s).

About 3 days before feeding her I added a humidifier to bump the humidity up from 45%~ to 60%~. The humidifier puts off a very mild hum/vibration, so I'm not sure if that upset her (though I would think that she would regurg more quickly if that's the case, instead of vomiting days later).

We also have 2 dogs and 2 cats. One of the cats has recently taken to sitting on top of the wood we have for the cage cover, and our dogs are very rambunctious, always running and jumping around the house. Not sure if this stressed her out, but once again I would think she would have very quickly regurgitated if that were the case...

Nonetheless, I'm kinda lost as to what the cause may be... If any of you have some experience here, please chime in. It's my first snake, and though I've read a Lot about snakes and boas in particular, I'm very much looking for some insight here.
Thanks guys!