I do believe that the side effects of using OC on her could have been far worse than the Tazer. Like was stated earlier, after a minute or so the subject is no longer affected. With OC, you run into the whole "breathing" issue. There is no "clean up" with a Tazer unlike with OC.
Having been exposed to both, I would much rather get Tazed 100 times then be sprayed once.
Had the officer sprayed her, the debate would have been why he did that and not Taze her.
Given the options on non-lethal force, Tazing is the best way to go if you are the one it's being used on. One short ride and it's over (unless you still do not want to cooperate).