if she is not happy, her complete immerision will only end in a complete hatred and disgust for the beasty.
Maybe. A possible problem with that is that if she becomes completely immersed and isolates herself from the real world, she'll have nowhere to go if/when the going gets rough. And why would it get rough for her? She won't have any financial problems. She has a bit more freedom than most witlesses because she can let her hair down a bit with you, so she's unlikely to feel completely oppressed by the borg.
I think the idea to show her the contrast is a good one. Christmas might be a good time. Don't buy her a present. Visit family or friends for Christmas dinner on your own. Buy a Christmas tree.
Just some ideas. I'm no expert, but I hope that helps anyway
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Those who can induce you to believe absurdities can induce you to commit attrocities - Voltaire