This person is way beyond drop the rope. You need to just go full NC on this drama queen.
You're concerned about whether she sees you've read and not responded. Just block the toxic cow and have done with it. She's the sort that keeps pushing and pushing for attention, she'll look elsewhere once she realises you're not playing anymore. You don't have to let anyone into your life who gives you this much drama. And block anyone else who is her "flying monkey" who tries to drag you back into this shitshow.
If you really can't block her, don't open her messages from now on and don't look at anything.
If she turns up at your house, ignore her. If she doesn't go away, just call the police and tell them she's harassing you.
If she lies about you to other people, just correct them (if they're likely to listen) or just tinkly laugh and "oh she tells such tall tales doesn't she haha so anyway what did you think of this new TV programme...?") so you're not even engaging. Stop being so earnest about it all because that's why she's targeting you.
If she sends you a present, a card or some nice message (or gives them to someone else to give to you) just send them straight back, unopened, or bin them. Don't let her guilt you, the "nice" aspect is just more manipulation to keep you in her circle.
Just stop letting her control your life and stop enabling her behaviour by pandering to her when she asks things like "did you mean to hurt me by (insert bullshit here)?" decent people don't talk to each other this way and she's not worth explaining yourself to.