Hi Phillip - since Mavis is feeling a bit off I thought I'd pop in.
Have they gone back to the nest yet?
There are many reasons why birds might abandon a nest. An overeager owner is definitely one of them! It's so exciting we want to check in all the time, but it can have sad consequences. If at all possible you should leave the birds alone except to feed and water them. You also want to leave them alone as much as possible after the hatch for the first week or so. Parents have been known to stop feeding their babies (or even eat the babies) when stressed.
New parents or first time parents also may not have the hange of nesting yet. It might take 2 or 3 clutches for them to figure out what to do. I'm still working with a pair of macaws that were great breeders, but their owner never let them incubate their own eggs - consequently we've had two clutches already where the female sort of has the hang of it, but not well enough to be successful. (We lost 4 fertile eggs letting her try, but in the long run it's better for her and them).
Has anything changed around their nest? Loud noises like nearby construction or anything like that? Environmental changes can make a difference to some birds as well.
Hope that helps some.