When your wife comes to her first event, she'll get a spell book tag with the spells she knows on it, and the other ones crossed off. So, she'll know all 1st, 2nd and 3rd level spells, but then will have to choose 1 spell from 4th to cross off, 2 from 5th, 3 from 6th, and everything from there up would be crossed off. She can then memorize the spells she wants from her spell book. For more spells, she can buy/find/borrow/etc. a full spell book from someone IG.
Best,
Ian
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