New eggs on the nest after 2 months!!

Hi. I need to share something to you guys and i know that this has been asked before but i need your help!

I bought 2 parakeets last August 2013 from a local pet store and I raised them to breed. Its been a while before Sasha (the female) parakeet to lay some eggs. January 13 when the first egg came then January 15 is the second then so on. She laid total of 4 eggs. 1 was unfertilized and the other one died when it hatch because it was eaten by ants..

The first one whose name is Janjan hatched on January 30th and the 2nd one came February 1 (name is Febby). They're both 8-9 weeks now. When they learned to fly I seperated them from their parentsi n a different cage. Then suddenly I noticed this afternoon that Sasha laid an egg again. Then early evening there's 2 of them in the nest box. Sasha was never seperated to the father Dwight. I just wanna know if this is something normal or is it something alarming? I dont have any plans of seperating them because they were so cute and romantic together. I just dont want Sasha to lay eggs every other month for it might harm my darling pet.

Please help me decide what to do Thanks!