When I got mine she did not eat for about a month. I got her in winter so I was not as worried at first, but she was not eating any of the stuff people told me she would.
Finally, I got some purified water and took a sofy dropper and put a drop on her mouth. She let it run off, as would be expected. I tried prying her mouth open (gently) but felt that to be a bad idea. Then I brought the dropper around in front of her and moved it around like a bug, with a drop hanging off. She hit with with her tongue and drank the water. I did this a few more times, and each time she drank the water. Then she started eating.
It seems she was dehydrated when we got her and getting worse. The petshop used to let her sit on her heat light.
This was a few years ago, so it must have worked.