Hello from JustAnswer.
If your aunt is suddenly worse, then she should be seen quickly. Even if she does have Alzheimer disease or another chronic dementia, a sudden worsening is worrisome that there may be an acute infection. Even relatively minor infections, such as a urine infection, can cause a person with Alzheimer disease or other dementias to get suddenly worse, and it would be better for her to be seen urgently to get any such problem addressed. Since she does not have a regular doctor, then it would be better for her to be seen in an urgent care center.
For chronic symptoms that are worrisome for Alzheimer disease or dementia, it would be better for her to establish with a primary care physician. There are many good primary care physicians in Sacramento, but the issue also is finding which doctors may be able to see her in a timely manner. Frequently, the best method for getting quick appointment would be to use a physician referral process. The doctors at UC Davis are very well rated and they offer a referral web site at http://www.ucdmc.ucdavis.edu/medicalcenter/findadoctor/.
If you are uncertain about whether there has been a sudden worsening, it would be better to have her seen urgently, and then any acute illness can be identified and treated, and if the only issue is the chronic dementia, she can then be established with a primary care physician.
If I can provide any additional information, please let me know.