No, this is not normal. Have you checked her crop each morning? Her crop should be full in the evening and empty before she feeds in the morning. If her crop is not emptying overnight, it is possible that she has an Impacted Crop, and if left untreated can turn into sour crop, a whole other issue. See a link at the bottom for a description.
The liquid you're seeing dripping from her mouth is likely fluid that she's taking in, but it's not reaching her system because of the blockage - this is a dangerous time for her too because she's getting neither nutrition nor fluids, or a much smaller amount than she needs to survive.
If Impacted Crop, isolate her first and withhold additional food since you'll only be adding to the problem. You'll need to get a lubricant into her next. Some use mineral oil, others use vegetable oil, some use olive oil, and still others use coconut oil to help lubricate what is currently in her crop to help her move it from the crop and into her digestive tract. Coconut oil can be frozen into pea-sized pieces and fed without much trouble. The others will need to be syringed into the bird's mouth about 2ml to 3ml (2-3cc in a syringe) at a time. If you don't have syringe, some folks have soaked small pieces of bread in the oil and hand-fed the oil-soaked bread to their birds. Use what you have or can get your hands on.
Once the oil is administered, massage the bird's crop gently squeezing and releasing the "ball" that you're feeling in her crop. Massage side to side and top to bottom too. You're trying to mix the mass that's blocking her with the oil or coconut oil to help it move on out of the crop. I'd start this process ASAP rather than waiting for morning to start if this has been going on for days already. Feeding her a bit of yogurt will help to stave off Sour Crop too and help to moisten the contents of the crop.
Make sure she has clean fresh water to drink while food is being withheld; she needs to remain hydrated as much as possible, and the water will also help soften the crop contents.
Here's a good description of how to administer liquids to a chicken if you've never done it so that you don't aspirate them:
https://bitchinchickens.com/2020/02/06/how-to-safely-give-oral-medications/
Here's a description of Impacted Crop and how to treat from PoultryDVM:
http://www.poultrydvm.com/condition/impacted-crop