Her humidity is too high unless temporarily when she's in shed; you want about 55% routinely- but I doubt that affected her stool anyway.
I wouldn't rush to the vet with this stool either- it can vary some- just watch it- see if abnormalities continue or worsen. Bigger concern would be bloody stool (or orange color).
Also bear in mind that rat pups are very digestible- not a lot of roughage so the resulting stool tends to be softer, less formed- & the pup was probably full of milk- that might be why her stool was lighter color- your snake didn't completely digest it all so well?
It's a bit unusual for a BP to be "exploring" so much (even though it's fun for us to watch) because it often means they're not feeling settled in- maybe hides aren't suitable & she feels stressed. You didn't mention what kind of hides she has or how many?