Talk about them I can! No, they don't plan on breeding them again.
Basically what happened, was they though Sparky was infertile. They gave her a certain kind of birth control a long time ago that coated her eggs in a gel so that sperm couldn't enter them. They thought it had coated all of her eggs. (she mentioned they kind of wanted Foggy and Sparky to breed, but they never did) While with Lobi she was still one one type of birth control, just to be safe.
However, after many years, they figure she finally expelled all of the gel covered eggs, and is now ovulating with healthy eggs that can accept sperm again, so even though she was on BC at the time she still got pregnant.
Currently, she is on two new different types of birth control, one is an injection and she keeper didn't specify what the other was. Sufficient to say they don't want her getting preggo again. Additionally, they didn't even know she was pregnant until she expelled the two stillborns. It was a complete surprise for them.