How long do the Snow Fairies have to set in my inventory before they are counted for the achievement? I have them all, they are all check-marked on the list, but it isn't registering. I don't want a gremlin to swoop down and fly away with them.

As soon as you have them all in there the achievement should activate. Try refreshing on your inventory once?

My achievement showed up as soon as I dropped them in my inventory and went to look at my inventory page. If a hard refresh doesn't do it, you may need to file a ticket.

Yes. Thank you all. It came up shortly after I posted this.