So my first question is how many home invasions are there in Emporia Kansas? I am guessing that it isn't the crime mecca that some place like Camden NJ is. How often are those burglaries that do occur, occur with intent to do harm? I don't know, so before I start poking fun, I thought it good to ask.
Are there only 2 floors? A main floor and a basement? Three floors: Main, Upstairs and Basement? Does the basement have an external door (growing up we had a basement with a sliding glass door)? Do the kids know the neighbors well? Are you comfortable with them?
Typically the best thing to do is baracade yourself in one room. Contrary to popular belief, this doesn't mean (necessarily) sliding your wife's armoir in front of the door. What would be better is if you could get to a place that had a choke point (say the bottom of the basement stairs if they are close enough to the family). That is thing one, thing two is that while the wife doesn't shoot, she can still be eyes on your six with say a cell phone in hand placing a call to 911. You're going to want to do that anyway, and let whom ever is in the house understand that you have done so. This may not scare them (which means they are really bad men) but it will record the entire interaction if shots need to be fired. You may even want to say something like "whoever is in the house, I have called 911 and have armed myself (assuming that you have) and I will respond to any movement in my direction as a threat to my life and will respond accordingly, the police are on their way, I suggest you leave!" Generally it is best to be baracaded by this point, and not a good idea to go roaming through the house looking for a fight. If that is what you need to do to get to your kids however, I would recommend it. Get the entire family in one spot, if you can't get whoever isn't with you to a safe place, if you can't probably getting one parent with each set of kids is the next (read last) best solution. If that is the case, tell your wife that she should learn how to shoot at least once, teach her something simple like "extend, touch and press" and let her take care of the girls.
There really isn't a clear cut answer as all situations depend on lots of factors. Some factors that don't change are your preparation. You should always have the cell phone charging on your night stand, a flash light next to it and your gun someplace where you can get to it quickly but is also out of childrens reach. Next make sure you have a plan and rehearse it so the family knows it.
Hope that helps
JB