You cannot comprehend why she agreed to 'take his points' unless you have lived in a similar relationship.
She was earning more than him during their time together (as was I), so financial reasons do not explain it.
You cannot comprehend how 'control' creeps up on you insidiously, and you don't realise or understand how or why until you get release from it.
PS it is akin to Stockholm Syndrome
http://en.wikipedia.org/wiki/Stockholm_syndrome