Virgin Corn Laid Fertile Eggs!

I have a ghost corn female that I kept seperate as she was not eating very well and regurgitated a lot. As a result she took rather long to grow. In breeding season I noticed that she looked gravid but didn't worry too much as I knew she had never been with other snakes, let alone a male - since she was a hatchling. However, she went on to lay 8 fertile eggs that all hatched! The babies were all perfect but all were strange and unusual colours (beautiful colouring). None of them were ghost corns though. Has anybody else experienced anything like this? Furthermore, she was only 18 months when she laid and I would never have paired her up anyway. We've had a couple of young snakes lay infertile eggs without having been mated, but to have a virgin snake have 8 fertile eggs - that is wierd? I'd be very grateful for any ideas?

Many thanks,
Chantel (SOUTH AFRICA)