You have my thoughts and sympathy mate. It's a choker. ..mine had a similar upbringing. ...too many siblings, not enough food. It's doesn't give them the right to ride roughshod over all and sundry....especially to the likes of us who's took them out of that dire situation. I will add. .my wife got a sister. .she's solid gold. .an absolute diamond. All becoz someone's come from an impoverished background doesn't mean they are going to be your worst nightmare.
I won't be taking that chance again though.