Short answer to the crop question, impacted crop can kill your bird. Longer answer: Think of their crop as a grocery bag that the chickens store food in and then when hungry, move into their digestive tract to be consumed. If it's impacted, then food is going in (and fermenting), but not...
Excellent, that is as it should be at night, please be sure to check it again in the morning BEFORE she's had access to food or water. You'll be wanting it empty by morning.
Please check her crop tonight at bedtime and again first thing in the morning BEFORE she has access to food and water. In the picture you've posted, I don't see her crop, and that leads me to wonder if she's being bullied away from the food. While you're checking the crop, you may wish to...