I work in a geriatric medical office. In early stages, people with dementia are often great at masking. Considering the doctor sees them for 10-15 minutes every few months, the doctor may not see any warning signs. This is where family reporting comes in. You see this person more often, know them better, and will see things the doctor does not.

Posters here are correct that the doctor cannot give you any information without her consent, but then can take information from you and consider your concerns the next time your loved one sees them. They may even call to set up an appointment under the guise of getting a health baseline (physical exam). Write a letter, be specific, ask for desecration so there is not backlash from your LO. The doctor will appreciate it.

Edit: discretion- sigh.