One of the most common primary causes of vaginal pain during intercourse is a dry vagina. Usually, when a woman is sexually aroused, fluids are secreted in the vagina that keep the lining well lubricated. But if a woman is not sexually aroused, or if fluids are not secreted for some other reason, intercourse can cause very painful damage to the vaginal lining. And in some cases, the lining of the vagina can actually tear, resulting in post-intercourse bleeding.
Another common cause of vaginal discomfort during intercourse is bacterial infection. This occurs frequently in women, and an antibiotic will generally cure the problem within a week or so. A related problem is bladder infections. While the problem may be in the bladder or urethra, not in the vagina, it often causes discomfort during intercourse.
There are other diseases that can cause pain or discomfort during intercourse. Vaginal endometriosis is one of them.
She needs to go to a doctor asap.She should be able to go as a walk in if they don't have any appointments available for her now. As mention in the above post it can a uti but she needs to be examined by obgyn.