My wife is one of those who couldn't care less about what's in the BoB, but I've put together one for her anyway. It is (more or less) designed as a stand alone BoB in case we are separated or mine is lost, stolen, burned, or otherwise unusable. I carry the heavier items and hers has the lighter items when it's feasible. Hers only weighs about 14 pounds without her "personal things" and mine is a little over twice that. We double up on guns, ammo, knives, etc. and she carries some food. She carries her own clothes, water, and personal items. She has the canteen stove and a few Trioxane bars and I have the folding stove and more bars. I have the tritium military compass and she has a Brunton 9020 (and we both have pin on button compasses). And so it goes with all the gear.

I'd pack essentials in both, and different nice to haves in both. The real essentials (light, fire, whistle, blade) don't take much room and you might lose one pack.

I started my wifes BOB and all of a sudden it became a family project that we both enjoyed putting together. Then we went on a "camping trip" and was able to practice using all the equipment. Not only was it fun but it also made us re-think a few things. My wife carries a lot of redundancies to my bag, but she also carries a few things that I dont have in mine. Her's is about 37 lbs. and we go for walks with them on. Not only is it great exersize but we - again get to spend some quality time together and she is now "equipped to survive".

I don't have a wife, but I did build a BOB for my friends daughter. I wrote on waterproof paper what the items were and how they worked.
Fieldddoc

I just put together a BOB for my daughter who is attending a university`in another city. Her multi-year boyfriend is at the university as well. The primary threat to her is the second largest refinery in the country being next door and up-wind of the university. Her boyfriend is an Eagle Scout but has no BOB. I packed basic equipment for the bag but included extra rations for him as well. I have asked him to put together a BOB and he can use the "extra's" that I have included in her kit, which will then lighten her load somwhat. Besides her car as the primary escape vehicle, she knows to "hang" their bicycles on before Bugging Out, as secondary vehicles.
When one refuses "to get it", the "realistic" one must allow for it and prepare anyway!