Looks great and you may want to put an old blanket underneath and around the box for in between delivery's as it can be a bit messy and stain,also a heatpad for babies and mum would be good
Eggyolk with a little probiotic yogurt and raw redmeat(if she'll eat) is great for expectant and nursing queens,kittenbics,pretty much as much as she'll eat and anything within reason.Make sure you see each placenta after each kitten,sometimes mum will eat it this is okay but sometimes they don't.All being well she will do the work,just be on hand for verbal support for her and we'll all be here for you and our numbers should you need on the spot right now help can be found via public profile(they'll be links to any of our sites where you can get in touch fast)Good luck for a healthy,safe delivery and do try and keep us all posted on any news