Hi
Girls DO Spray and some are very good at it!

All of my whole girls spray once they have had a litter thats part of breeding...
It is because they don't want to share with other cats... It might be a good idea to get yourself an outside housing for your girls one for each, lined and insulated and heated of course but a least you can keep on top of their spraying.
I bring my girls in daily to play and if they are PG or have kittens then they are in our home.
But spraying does go with breeding not just because they are bengals
Hope your girlies are being good!
Caterina