Before you build her a system, sit down and put together a plan. Figure out if you are staying in place or going somewhere. Your main issue is what are we going to do. Stay away from the commercial one size fits all backpack kits like Walmart. This may sound crazy but go to FEMA site and get their list of 72 hour needs. It doesn't cover defense because it is FEMA but look over that. Make your plans so you know how you need to approach the day that is coming.
Prepare for 72 hours first. that is your carry kit. Things you need for the first three days. And then build up your first 2 week kits and then 3 months. Water, food, clothing, shelter, heat, light, meds, compass/maps, money, tools(multitools/swissarmy knife), Sleeping system, hygene issues, extra glasses, and so on. Be sure you have a manual can opener. Go to information on this site and others. Have non battery powered products if you can. A wind up watch, clock, crank flashlight. You have to determine what in the way of self defense items you may need. I don't know your view on guns for example. Don't give a gun to someone who doesn't know how to use it properly. Good luck and let us know if we can help you.
You can Google for "72 hour kit" as well. There are lots of good lists. As for brands there is so much choice and so much depends on your style and price range. Aside from certain must have thing like multi-tools I suggest buying inexpensive items at first. It would be a shame to drop $500 on a pack and find you can not stand the pouch layout.