Just got a new kitten today

As the title says, I just adopted Memow today. I've had family cats before, and lots of experience with irresponsible friends and family members that leave unspayed/neatered cats outside and end up with kittens. So, I have second hand experience, but this is my first time with my own kitten and I want to do it right.

She is fresh out of spay surgery, so lots of huge scary changes in one day, and understandably, she's still hiding in the carrier. I opened the door and put food and water just outside. Normally I'd just leave her alone and let her adjust, but she purrs when I lay next to the carrier. Should I still leave her alone? Or is me being nearby comforting her? Would calming treats help with the transition? I'm not sure what to do here, but I know she's scared so I want to make everything as comfortable as possible.