Well get the girls shooting that shotgun so they are not afraid of it.
That piece of mind knowing it's there for them when your not would help. Also you need to take striker off the door frame for your deadbolts and replace the screws with 4" wood screws. When someone kicks in a door the door don't break, the jamb does. Replace all the stricker screws with 4" that will put the screws into the studs around your door frame. That will take alot of abuse before it gives in. Plenty of time for a 12 ga. to plant itself on the inside in case it does come open. Do this with every door you have. The home depot sells a little window alarm that gives off a pretty loud siren if opened, 1 aa battery and double sided tape and you will know when any window is open. $10.00 to secure every entrance.