You can read messages on messenger but choose not to 'accept' it so the sender thinks you've not seen it when in fact you can read the whole message without the sender knowing. My friend was doing that for a while until I said to him I know you are reading them and then he just accepted them.
This is correct.
But also if you click ignore it blocks the sender from sending anymore, and we had sent each other messages before so unless she deleted the whole previous convo then it should go straight to inbox without being friends anymore. This happened with my brother.
Otherwise it goes to message requests which if you don't look you don't see, again this is not foolproof as sometimes I have had a notification for messages form non friends and sometimes not.
Either way I would think if she has seen it she would have blocked me now, it's her ultimate f you to people (blocking o FB).
That's why I think she thinks unfriending is blocking, I remember once someone at work was messaging her who she thought she had blocked but only unfriended, I had to do it for her (block them).
