First Time Wanting To Act On Seducing My Sister

Have been obsessed over my sister for over a year now(20M)and (38F). We have a regular relationship/Passive Aggressive we have had one incident when she confronted me , She’s 180 but i love her figure, she has no husband and hasn’t had sex in 6 years since she only works and is a mother. I believe that she could be missing out on some feelings. She Doesn’t go out beside going to visit family. she lives with me and our parents house but we spend some time together alone, and are both up late and early since we get ready around the same time. Is there a chance, How should i approach Any advice?