What substrate are you using in your lay box? If the eggs were like that when you pulled them out of the lay box is means that either the substrate is too dry or they were in the lay box for too long after being laid (as in several days or more). I like using moist bed-a-beast in the laybox with a layer of moist spagnum moss over top of it.

I supposed adding some spagnum to your incubation material wouldn't hurt if it is too dry, but I would simply add a few drops of water around the drier eggs and bury them a bit deeper so that they are more covered by the moist substrate. I have done this many times with crested eggs that got too dry before I pulled them from the lay box and it works like a charm.

Your mack snow is 100% female and really cute!