To better understand what I mean by this, go into a lit room and hold your hand a foot or so above the table. You should see darker shadows and lighter shadows from your hand cast onto the table. A penumbral eclipse occurs when the lighter shadow from the Earth strikes the Moon. Unless you are paying very close attention to the Moon, you probably will not notice any changes.
|A lunar eclipse occurs when Earth casts a shadow onto the Moon.|
Since this doesn't sound like a very exciting lunar eclipse, when is the next full eclipse? There's another penumbral eclipse on May 25, 2013 visible in the U.S and another penumbral eclipse on October 18, 2013. But those won't be very exciting either. The next full eclipse visible in the U.S. takes place on April 15, 2014. Total lunar eclipses visible at your location are much more common that total solar eclipses, but it can still be a couple of years between events.
I don't discourage you from taking your kids out to observe the penumbral eclipses. It's quite possible you'll see something to share with them. But definitely make plans for the April 15, 2014 eclipse!