Wow! She laid an egg!

Our parakeet has been acting weird lately too, especially around my husband and we think he may be a she since the beak has changed from blue as a baby to brown and our bird won't be 2 until this summer. If our bird lays an egg we will know for sure that it is a girl! Also T-bird has been chowing down on his/her cuttlebone, we just got a new one for Christmas, maybe it is the calcium craving! I will also be interested in any replys you get about female parakeets and cockatiels laying eggs when the reach maturity.