I'm still at a loss to know what your beef really was though B?
You disliked your step daughter in law because while living with you and working and saving (though you choose to disbelieve this despite their moving out as planned) she didn't clean the house because (and you choose to disbelieve this also) she was also sick with Lymes disease while working.
Your son in law (I note you tended to de-humanise these people with abbreviations?) apparently you were less pissed off with, despite not working at all and sometimes cleaning up after his various kids by ex-marriage who came to stay at weekends.
This whole scene lasted something between three and four months - a tiny amount of time. In which time you also started to freak over the idea that your ten year old grand-daughter by marriage, might be sinisterly attempting to wheedle her way into her Grandma's house!
Ever consider you might have your own issues around having an in-law family?