It's a relationship and takes both of you, and your half has to decide for your half; it's not giving the other person a "chance" like you are doing them a favor or feeling sorry for them. If you are over her and feel like it might be a hassle and leave you feeling worse, I would move on. It does sound like she is lonely because of how she is treating her other relationships and feels you respond. You are not someone else's way out of loneliness, you are looking for a partner.