my wife and I have been married for over 12 years and together for almost 20. We have sex about 3 to 4 times a week. It can be hard to find time for each other. My wife works on the weekends when I am home, and I have to be in bed early during the week to get up at 4am to go to work. So it can be hard. Plus you add in two kids that take up all your time, which I am fine spending my time with the kids; thats not the problem.
I find that if you find a babysitter every now and then for a night out helps alot. Also add some spice to the bedroom with lingerie and toys.