Moving into memory care?

My sister owns her own condo and lives on her own. She has the help of Pace which is a service for the elderly. My sister has been one of the most "interesting” clients they have ever had. She is afraid of losing her independence and doesn't understand her dementia. Yesterday Pace had a team meeting and all voted that they wanted to invoke me as her healthcare proxy. She definitely needs to move into assisted living. Last fall they assessed her for assisted living, But now I think she would need more care. Any advice for me on how to tell her the move is necessary? We are all pretty sure she will resist. Thank you