#1 I would try worms (mealworms or others that have been recommended in reply to your message). Crickets can really "bug" lizards because they crawl all over the place including on the lizard. So she may simply be annoyed with her food. Put worms in a shallow dish. When they warm up, they'll wiggle. You can even try feeding with tongs.
#2 Make sure she has a dark hiding place over a warm spot as well as a dark hide in the "cool" side of her tank.
#3 As already recommended, make sure she has a container with vermiculite or some other sterile bedding material that is moistened but not wet. A clean plastic food container with the lid on and a hole in the side is great. The lid helps contain the moisture so it's humid to aid shedding. My geckos love to just lay in there nearly every afternoon, shedding or not.
#4 Try covering her tank (don't get the cover near the heat source) to give her some privacy for a couple days.
#5 Have you checked her belly for eggs? They should be visible as elongated white orbs on either side of her belly (two). Leopard Gecko breeding season should be ended now (although I actually got one late egg two weeks ago), but it's possible she's egg-bound. If so, this will likely require vet attention.
Some notes: If she's not eating, once she has cleared her intestines, she should no longer be pooping. Clean her cage well then watch to see if she poops anymore. Maybe she has eaten a cricket or two that was hiding and you just don't know it. How fat is her tail? If it's nice and fat, you don't have to panic. you can try the above and things others have recommended over a reasonable period of time. Just watch her tail, because when she's not actively eating, her body will consume the fat stored in her tail. What kind of substrate are you using? It's possible she has ingested some (e.g., sand) and has an impacted intestine/bowel. This will likely require a vet visit.
Hope there is something here that is helpful. Good luck.