Give the female her own enclosure as fire skinks diet is varied and they will eat eggs of even their own species, you will double the chances of this if you keep her with the male. A 1 gallon rubbermaid shoe box full of moist substrate is adequate for egg laying site. For substrate, I use the fine grade coconut fiber bricks that expand when moistened, it holds it's shape and allows them to burrow. Your female will spend most of her time in this box, coming out at her normal daily feeding time. She'll get plump, then won't come out for a few days to eat. When she does come out she'll be notably thinner. Remove the eggs and incubate on moist vermiculite at 80 degress for 50 - 60 days. If you leave the eggs with the female there is a chance she'll eat them. This all assumes the female is fertile, I cycle mine cold in the winter to assure the natural cycles occur, if not cycled the female may not produce eggs. After she lays she can be re-introduced to the male for a week or two. Expect a clutch of 4-6 eggs every 30 days until October when you should give her a rest before cool-cycling them again. Babies need calcium/D3 supplementation or UV lighting to avoid MBD. You'll need your own cricket colony or you'll go broke feeding them all! Good luck!
Paul