This thread might give you some info that you might or might be able to use.
https://discussions.apple.com/thread/5645477?answerId=24063119022#24063119022&ac_cid=tw123456#24063119
Also, remember that you get 90 days of free phone support once you buy them. So if you want the minis all set up and fully charged so your children can use them on Christmas morning, you can always call them for help. The cellophane will be off, but you'll probably wrap them anyway, and they'll get to enjoy them right away. If you decide to set them up with their own ID's, you can also give them itunes/app gift cards and allow them to pick some games, or preload the gift cards onto their minis (though they shouldn't need their own ID's for that.)
You can also share your itunes library with each. Just set each child up wiht his/her playlist in your itunes account and you can put the playlists on their minis. If they have music cd's you can upload them onto your computer, put them into itunes and their playlists and upload to each.
They're expensive enough, but given that they're children, you might look into strong cases for the minis and consider the Apple Care + which allows two replacements if they break the glass, spill liquid on them etc. Read the rules before you buy it. Headphones are not included.
Just thought of this given the above info - if you're planning on giving them the non-retina minis which are $299. for 16gb, you might look in the Apple online only certified refurbished store. The 16gb is not there right now but I think it's $229.00, so you'll save on that. Right now the 32gb is $329.00, so for for $30.00 more you'll get twice the space and they won't bother you for a long time as they start to use up space. Remember, you can't add space. (A new 32gb mini is $429.00 at Best Buy.)
Each Apple refurbished ipad (any version) comes with a new front and back cover, a brand new battery and a full one year warranty with 90 days of phone support. Each comes in a white box like a new ipad with the wall charger and usb cable. The only difference is that it says in small print on the bottom of the box that it is Apple certified refurbished. If you go that way, put a Christmas sticker on it with a child's name on each. Also, if you buy refurbs, be sure to check the store many times a day. They can come and go quickly, so when you see what you want, but it right away. Shipping is free and pretty fast. (We bought two a year and a half ago and they have been great!)
They'll be thrilled with such great gifts! Enjoy their joy!
Hope this helps.
