Does anyone have experience with hiring a home care assistant to care for an elderly person? Perhaps in the DC area?

My nearly 98 year-old grandmother lives in a senior living apartment complex, and right now she has someone who comes in twice a day to help her with her medication and, I think, someone who comes twice a week or something to do laundry for her. But we’re getting to the point where she really needs more hands on care and perhaps someone to be with her in the apartment all day.

Anyone have any experience finding and hiring this kind of help? Are there services or lists? How does one even start to do this?