i made a water spell, but my pet can't use it because she has no alchemy points. what's up with that?

You can read books to your pet to get Alchemy points. Did you pet read enough books?

You must have 16 intelligence points for each alchemy point. Reading is the cheapest way to get those points.

you buy them and read to the pet. Or you could do mystic spindles or other stat boosters.