Somewhat Confused

Hello all, I'm new here. I am a widower who is dating a widow. I lost my wife to cancer and she lost her husband in an accident.

My issue is we have talked about getting married, but am not sure we are ready. She still wears her late husbands wedding band. For some reason this bothers me. I want to marry her, but am afraid she is still committed to him. I don't want to be in a relationship with her AND him. So am I crazy and over thinking the symbolism of the ring? She said she is ready for a new life with me but the ring for me is an issue. She isn't wearing it on her ring finger but it is on her left hand.

It bothers me so it makes me think she might not be ready and since it does bother me am I really ready? What are your thoughts?