How do I keep my house gecko from leaving?

In 10 years we’ve only seen geckos in our house twice, and both times the cockroaches disappeared. We’ve recently been blessed with a gecko and the past six weeks have been amazing. Is there anything we can do to keep our little mo’o thriving? Obviously we’re doing our best not to squish her in door / jalousie accidents but other than that? What if she eats all our bugs and leaves??