Be prepared to monitor very closely for internal pip of either chick. Neither one of them may be able to get into position to do even that, and you may have to assist. But it's difficult to know exactly when the timing is right for that, as one chick may be advanced ahead of the other. Wishing you the best, but don't get your hopes up too far. Just consider it a bonus, if either or both hatch.
Ephesians 2:10 For we are his workmanship, created in Christ Jesus for good works, which God prepared beforehand, that we should walk in them.