Hi,
I breeded quite a lot of sternfeldi. (not rudis but I asume you've got sternfeldi as well).
I kept the babies in groups up to 10 animals the first weeks in terrariums from 25x40x60 or 40x40x60 (in cm.) and when they grew bigger I splitted them in males and females (which I could see after 2 - 3 months).
I gave them a spot for all day with interventions of 1 hour on and 1 off. And early morning 3 hours after eachother. With food I mainly feeded fruit flies (breed those myself) and after 1,5 month they could eat crickets but I prefered flies. Day temperatures where between 18 and 26 degrees depending on season and night between 10 and 17 degrees depending on season. I feeded every other day. Every day feeding is possible but I found them growing to fast then. For long living that ain't very well is my opinion.
You can catch fruit flies by putting some fruit outside in the garden, and just wait a few days. But there's a little chance you'll catch enough to feed your babies.
Good luck with them when they are born. I hope this helps a little.
Steven