Well, this situation happens often when someone sleeps with the contacts. At this moment, you can use eye drops, which are a very good idea. Also, you can use a thorough rinsing with cold water, so that it will not irritate the eyes. I would suggest that she should not sleep with the contacts, because it will damage her eyes and make the eyes infected. Only if she takes off the contacts, do her eyes have time to recover and have a rest.
You should not wear the contact lenses to sleep. The corneal lacks the oxygen which may cause your eyes to be blind. Your eyes feel burning because the contact lenses are sticky to your eyes. You'd better use the eyedrops first to release the dryness and then follow the normal procedure to take the contact lenses off. And I suggest you not to wear the contact lenses for a couple of days and let the eyes have a good rest.
It's common to see people who wear contact lenses have this problem. Because of there is no enough oxygen as well as moisture in the contact lenses, they becomes dry and causes burning eyes. Firstly, you should take off your contact lenses to relieve your eyes. And you can use eye drops to through rinsing with cold water thus not to irritate your eyes. After this step, you can close your eyes and take a nap for a quarter to rest your eyes.