I think it's worded using "spend" and "recover" because there are other things going on in the game that could interact with her ability. For example, if Lily were under some kind of curse that prevented her from "recovering" Health, she wouldn't be able to use her special ability to change Sanity points to Health points. But if it were worded using the word "convert", then people would wonder whether or not that curse affected her ability.
Fair comment on the use of spend vs convert - great example of unintended consequences !
The wording on the card is:
"Spend any number of Health or Sanity, then recover an equal number of Health or Sanity".
"Spend" is defined in the play book as discarding a token or tokens in return for an effect. I was looking for an effect for her to spend the tokens on. It as not obvious to me in the wording that the effect is the action to recover an equal number of tokens of the other type.
I think perhaps it could be written better to more clearly indicate the intent, but it's not something I'm going to lose sleep over !!!
Perhaps if they had included an example in the rulebook, it would have been helpful.
Absolutely - as soon as it was explained above it was pretty obvious. I found the examples in the rules/playbooks very useful in explaining other concepts in the game and made it very easy to get started playing.