Have all the spirit meddlers been cleared from my client and her former partner, whose relationship they undermined?

Both individuals have been effectively cleared of spirit meddlers. The problem now will be keeping them clear from new attachments. As you know, newly arriving spirit meddlers will look at the history of their new host and will quickly spot points of vulnerability that have been exploited previously by their predecessors. So it is quite possible that they will be back in the same boat should that happen. This means it is of importance for them to attend to their personal safety with a regular prayer of protection. They may need to have rechecks done by you as well, to help monitor things so as to head off a repeat of the strained relationship that developed from spirit meddler interference.