How do I know if mom has dementia?

She is waiting for dentures, meanwhile can only drink liquids. Her lips and mouth burn when she eats soft food. Of course she is losing weght. Leaking bladder is worse now. While she was hospitalized for UTI, she did not wear adult diapers . She is home now and wants to use just the diaper without the extra pad. She leaks urine in the bed even more than before. I put pads under and over the sheets. Also changes diapers in the bed. Other pain issues due to hip surgery and tailbone movement. Takes opioids for pain and to help her sleep. Doesn't want to get hair washed or get a sponge bath. SHE told me to leave her alone. I am at home all day due to early retirement. The diapers and over the counter meds are expensive. She does get meds that her doctor prescribes. At her doctor appointments she says that nothing hurts , she feels fine.