What you'll need to do is offer the smallest food you can, and offer a variety. Some poor eaters will only eat certain things until they get going and then, they'll take other foods.
For example, my albino turned down mealies and waxworms but only accepted crickets for over a week. I had to get the smallest I could find and offer them daily. Now, I finally see that she sneaks a meal worm or two when I'm not looking. LOL!
Leos like to eat at night. Feed her in the late evening (their natural foraging time) to see if that helps.
Sometimes vitamin and mineral deficencies cause poor appetite, as does dehydration. If she's dehydrated, you'll have to deal with that first. You can give her bath in gatorade or pedialyte...her body will absorb the fluid and electrolites. There's also a spray vitamin treatment that you can get at the pet store.
If you absolutely must make her eat, the least stressful way to do it is to mix up some food and dab a little on her nose so she has to lick it off. If you force her mouth open, it could easily break, and force feeding tends to be morbidly stressful on them.
I'm sure others here can give you some pointers on "mush" food for her...recommendations on which baby food and what to mix in it. Can someone help us out with this, please?