***Not a teacher***
Your question is around the meaning of '...and settle them she would'She was really out (of prison), she was home. But she still had old scores to settle and settle them she would
In my opinion, there are a couple of possible ways of interpreting this.
If this is narrative from the point of view of 'she' (whoever 'she' is), then '....and settle them she would' is probably expressing her state of mind - in other words: 'But she still had old scores to settle, and she had determined in her own mind that she was certainly going to settle them'
If the narrative is being viewed from a historical perspective (i.e. we are looking back in time on these events, and with the knowledge that the scores were actually settled subsequently), it could possibly mean the following:
"But she still had old scores to settle, and in the fulness of time, we would come to see that she did actually settle them".