breeding between zebra/shafttail

Question
I have a male zebra finch and a female shaft tail finch that have coupled up.  He put together a great nest and she laid 4 eggs.  They got very aggressive with their cage mates and actually bullied and killed 2 of my other birds.  I took out all the nests and everyone has reverted back to relatively normal behavior.  If I were to cage these two separately and let them try again, are their eggs viable?  Will they hatch?

Answer
I would suggest housing them separately from the other birds since they will more than likely try ro nest regardless if theres a nest or not and they've already proven to be very aggressive. Shaft tails and Zebras do belong to the same family so their eggs MIGHT be fertile but would not suggest letting them have babies. The offspring would be infertile and could possibly be born with birth defects