new snake owner feeding problem

[Bogertophis]

If you warmed up the mouse when you first offer it, sometimes snakes have trouble finding the head & then it cools off so they lose interest.

Are you heating up the mouse's nose with a hair-dryer? Many here have success with that method, especially for snakes like BPs that have & use heat sensing pits.

Feeding at night (or evening) usually helps too, that's natural for them. Also, BPs are "ambush-predators"...many don't like to accept food unless they are peeking
out of their hide, waiting for a hapless rodent to pass by. If the snake is cruising their cage, they may feel too "exposed" to eat...remember that in the wild, snakes
have to eat fast, or risk becoming prey themselves. Swallowing prey puts them at risk, so they prefer to be stealthy.

She might also be going into shed soon: snakes can "feel" it coming long before we can see any signs of it, & many refuse food until after they've shed. Not to worry.

Few snakes are ever "aggressive" to us: they are defensive. We are big scary predators to them until they learn...be patient, try to imagine yourself in her place.
Snakes mostly bite out of fear & self-defense, or out of confusion with food (if we get in their way when feeding them, or have rodent scent on our hands, they rely
on scent more than vision and we just aren't appealing to them as food, remember that). Snakes do learn...up to us to be patient. That you obviously care so much,
I'd say she has the right home. We were all "new" at this once...you'll get there. Snakes are very different pets from most others...lots for us to learn & just being
observant helps a lot.

And Questions are why we're here, & we're glad to have you join in. Your English is just fine, and FAR better than our French, lol.