Do you feed at the exact same time every night? Try changing the water and cleaning the potty out first. When these are clean and back in the enclosure put food in her dish, talking all the time to her while you are doing these tasks. Your little one will soon get curious and come out for a peek - especially if you are ready with a tasty treat when she pokes her head out off her house.
Start by offering it to her at the entrance and give it up the minute she mouths it. If she takes it and goes back in to sleep that is fine. Don't hold onto the treat and pull it way to try and encourage her to come out - invariably this does not work! They are not that stupid. Patience will make this method work.
Never put any food actually in her house. After a few days put the treat just outside the entrance. Just leave it on the litter layer or on an empty jar lid.
If she takes the "bait" than slowly over the next few nights move the lid further from the entrance till she is out in the open before she gets to eat it. Hopefully she will then see she has a nice clean potty and will go for a wash. After she has done her ablutions you can try to play with her and see what mood she is in.
Make sure you do this as late as you possibly can AND at the SAME time every night. Hamsters are generally okay to be active after dusk so don't try this at lunchtime for example, 7:30pm probably at the earliest, but as I said as late as you possibly can. You can slowly move the time earlier over a number of weeks if you want to spend more time with her and she doesn't seem to mind.
Keep talking to her all the time you are in the room and always have a piece of her hamster mix ready to give her as a treat when she does come out to see what is going on. Treats don't need to be anything fancy, just a piece of regular kibble is fine.
You will soon find she comes out whenever you call her name no matter what time it is day or night - although she may take the treat and go straight back to bed again during daylight hours