about mating parakeets

My budgies are mating right now and I don't have any of the materials, How many days after they mate does she lay ...a myth, do I have to do anything for my birds? How many eggs do parakeets usually lay? What will the babies look like I have a blue and ... die? and anything else i should know please help oh and what about egg binding, how do i prevent it and anything else i need to know eek I'...

I have parakeets...I've had them for years and years and today for the first time I found an egg. I know I haveone  male ( he's very old about 13 and pretty close to the end right now) and now I knowI have 2 females .....to be a dud. I really can't imagine old Blue being up to the challenge of mating..Anyhow..we are leaving for vacation on Friday and I don't know what I ...