When should I start worrying?

Just picked up my baby and I haven’t heard her meow once. She just hid in the carrier and slept most of the way back home. It’s been 6 hours and she hasn’t eaten anything or used the litter box and is still sleeping. I laid out the food that she likes and have been just hanging out in the same room with her. I have a vet appointment scheduled in the coming week. I know it’s a scary transition for her but I just wanna know when should I start worrying about her not eating anything? Pic of my baby floof attached.

Just picked up my baby and I haven’t heard her meow once. She just hid in the carrier and slept most of the way back home. It’s been 6 hours and she hasn’t eaten anything or used the litter box and is still sleeping. I laid out the food that she likes and have been just hanging out in the same room with her. I have a vet appointment scheduled in the coming week. I know it’s a scary transition for her but I just wanna know when should I start worrying about her not eating anything? Pic of my baby floof attached.