How should I go about this?

Hello everyone, I recently got a job as a nanny for some babies. They are very young and a LOT of work due to their age. Anyways the parents are only paying me $12 an hour to care for them both. I plan on moving out of parents house and into my own within the next couple months or sometime next year but with that kind of money I can’t do that. I’ve been looking for other jobs that pay way more that I’d also have the ability to move forward with and have benefits. What would be the best way to let them know that I’m no longer available to help them?