You're off to a great start, Krista! The most important thing, in my mind anyway, is to get started. You can tweak and adjust along the way but you've got a lot of basis covered already by starting with what you have on-hand. Well done! (I cringe when I hear people who no BOB or an incomplete one because they are waiting for just the right piece of gear.)

I like that you're giving your 6 year old her own pack. Great idea! Don't overload it but give her the basics and some comfort items - perfect!

Shelter and water seem to be big gaps, but it sounds like you have a plan for those. Get what you can afford and then use it. You'll not only get proficient at it, but you'll uncover short-comings and find solutions for those. Don't wait until TSHTF to realize your tent leaks or your tarp isn't big enough. Since you asked, I'd vote yes to adding sleeping bag(s) or some other warm blanket(s). It'll be snugglier for your daugher. Don't underestimate to value of security, especially when there are kids involved.

Watch those Coghlans Fire Lighter sticks. We tested them this summer and though they're cool and can be easy to use, they don't work well if they get damp. (They'll crumble and won't ignite.) Keep them in a sealed ziplock bag. One of their plusses is that they are a great way for our kids to learn to start campfires. (They work just like matches, in theory, but burn longer and provide their own tinder.)

I'd considered adding some OTC meds specificially for your daughter. A sick child will put a major crimp in any bug-out plan. We proved that theory this summer on a simple overnighter. Where a adult would more often that not try to push through, a child is going to end up a whiney uncooperative mess if they get sick. Kids bandaids might be a nice touch too. In a bug-out scenario, she will be scared and something like a scratch could be a major ordeal. Something simple like a Hello Kitty bandaid could make a positive differenc. You're going to carry bandaids anyway so why not add a little ray of sunshine for her?

You might consider something like a hatchet or folding saw for wood processing. A good fixed blade could also preform the same role, assuming you're not going to be dealing with winters like we get in Nothern Ontario, which can quickly eliminate downed wood as an option.

Extra clothes is a big one for our family BOB. You won't be dealing with the climate we have here in Ontario, but at least one change of clothes could be a lifesaver if you add wet conditions to your scenario, especially for your daughter. Have you driven with her with wet unders? My kiddo hates it and gets whiney if he's soggy and tired. Whiney kids will not enhance your bug-out experience in a positive way. Keep yourselves warm and dry.

I'm going to go against the grain and say that I like MREs in a family BOB. Yup, they weigh more than dehydrated, but they don't need water or cooking and a timely meal - especially a warm one - will be worth it's weight in my mind, especially with a child in the mix. You might not want to carry enough to get you 400 miles but a few days worth could get you through the initial, everything is upside down and you need to get your bearings period. My kiddo's favourite is mac n cheese so we've got a couple of those in our kit, along with some things that he would usually only get as a special treat.

Everyone here has made some great suggestions so I'll second one of them as a final thought. Involve your daughter. Practice with her, but don't tell her it's bug-out practice. Make it fun. My son loves hiking, camping, bushcraft, etc... but he got there with a little encouragement and opportunities and without any worry about disaster. Teach her Hug-a-Tree, go on lots of hikes, camp. She may just grow to love it, which will make an actual bug-out gobs easier to manage.