You just recieved that snake according to a previous post.
Give her a week minimum to settle in and acclimate with no handling, then offer food.
And yes, changes in environment is very stressful for a BP, especially a baby.
A mouse pink is WAY too small for a BP, even the smallest baby.
Unless she is brand new and on something less than a few feeds I would not be giving her rat pinks either.
Newborns get week old rats.
Bruce