When a random YouTube sermon triggered guilty conscience in her, a primary school teacher must search for her elderly couple victims to confess her actions.

Logline is a touch long-winded and I think there are some missed opportunities.

I feel like a random youtube sermon doesn’t quite have the intrigue of just a regular sermon in a church (assuming it’s religious). It’s more visually stimulating and offers more insight into this character that you could delve into.

Maybe something along the lines of:
When a sermon triggers her guilty conscience, a primary school teacher must confess her actions to those she harmed.