Yesterday (Sunday) I woke her up for breakfast and played with her for a bit but she only ate 2-3 pieces of food. I put her back in her cage with the food dish and left her alone for the rest of the day until that evening.
Hedgehogs are nocturnal. I would expect her to eat much in the morning. Myself, I don't wake Sylvie up in the am past cleaning her cage & just a quick 'check' on her. Think of it as someone waking you up a hour or two after you've just fallen asleep.
I added her dinner portion to the breakfast (she hadn't eaten any more) and took her out and had her out all evening but she only ate about 4-5 more pieces.
Many hedgies won't eat infront of people. I think this is normal.
I put her and her dish back in the cage at my bedtime but when I got up in the morning it was still full.
Try counting the amount of kibble you put in in the evening and the amount left over in the morning. Eyeballing can be difficult.
Also her water bottle looks like she hasn't had anything to drink, maybe 1 sip, but I've never seen her drink.
Search the forum on waterbottles. While some people do use them, there's many posts about why bowls could be better.
When I got her out of her cage this evening her belly felt cool but she's warming up now that we're playing.
Watch out for cool bellies. What is the temperature of her cage? The temperature of her sleeping area?