Spaced repetition requires sincerity and discipline. You need to look at the question, understand it, decide just how well you remember the answer and act accordingly.

I don't think sincerity is such an issue with SRS. It's relatively easy to understand that it's unfun to have cards that you don't know at all coming up because you hit good the last time when you should have hit again.

As far as having to do it every day, I don't think that's true. If you skip a day that's not optimal and you have to answer the cards the next day. It will also be a bit harder to answer them the next day. I think that teaches something to the kid about consequences.