Is this a different bag of hay, or a different brand? Maybe it’s not as fresh or somehow not as appealing to her. Since she is eating her pellets and greens without any trouble, it doesn’t sound like she is having any teeth problems, although if this keeps up, it might be a good idea to have her teeth checked.
It could be that she has decided she no longer likes timothy hay, so try some other varieties or brands and see if she will eat them. Orchard grass is usually a hay that rabbits like. It is sweeter and a softer consistency. There is also oat hay and meadow hay, plus some others that you can try. If she only has first cutting timothy, you might try a second or third cutting timothy. American Pet Diner Timothy Gold is a second cutting of timothy.
You can buy hay toppers, which are dried herbs and flowers to sprinkle on the hay, or you could buy a small bag of alfalfa and sprinkle a tiny bit over her timothy. Alfalfa is very fragrant and the little bits can filter down through the timothy, making it more desirable.