I would be surprised if all six hatched, it would pretty much be a record I think ... And Donna is a first year female so not unusual for her to have fewer young, look at Radisson in Edmonton, only one chick this year, and I believe they are the same age.
I think the reason they haven't advertised the nest is that it is exceedingly inaccessible, you haven't had a pair for a number of years, its a new female and she laid late in the game, all/any of which could mean no successful nesting this year ...
I will certainly post an update about anything I hear !!