I love my girl budgies but sometimes I wish they were all males. Females can make great pets and my very favorite budgie, Rocky, is a girl, but breeding is not something you want your companion birds to do. Laying eggs, even infertile ones, is very common and problematic and egg binding can kill them.
Its not usually a problem if you have no more than two or three budgies but having a large mixed sex group stimulates breeding behavior especially if you give them a lot of free flight time. My vet says I've created the perfect environment for a semi-captive breeding colony. I joke about what would happen if I installed nestboxes around my living room at the top of the walls- I'd have to move out and let the budgies have my house!