My dog doesnt like her bed :(?

I just got a dog yesterday. Her name is Nala, and she's some sort of terrier mutt. She's a little bit bigger than a westie. Last night, i layed out two regular pillows and covered them with a towel. Today i went to petsmart and got her a bed. It's medium size, but im not sure if thats as big as she would like. i put another small pillow by her last night, and she really loved it. her new bed is orthopedic foam, so its bumpy and not that thick on the bottem. i put one of the pilllows i used last night under it, so it would be softer. i also put the towel in the bottem of her bed, because it seemed to comfort her. a few minutes ago she layed in her bed, and looked very comfortable. then she got out and spread out on the floor. i dont want her to have to do that in the middle of the night, because i really want her to be comfortable. i thought about taking the pillow off of it, but she seemed like she wanted it there. i cant buy another bed, i spent all my money on this one, because i thought it would be perfect. i really care about nala and i want her to sleep through the night. does anyone have any ideas that could help her become more comfortable? thanks in advance!!