If the bill succeeds, taxpayer dollars could be funneled to religious schools… including Satanic ones.
Hartley was essentially admitting that Satanists (and Muslims and other non-Christian groups) would theoretically have access to the funds. However, if the state had a really good reason not to give it to them, there was a way to restrict the funds from going to those groups. You don’t have to be a lawyer to realize that a group being considered a “fringe” religion would never pass strict scrutiny.
N.B. “Strict scrutiny” is a standard applied by courts, not legislatures, when reviewing a law for infringements of constitutional rights. It’s the highest standard of scrutiny, and when applied almost always ends with the law being struck down.
In other words, she’s saying that a law that excludes “fringe” religions would almost certainly be struck down.