This is a great space to visit with your family.  The park has a playground and several spaces that are perfect for a picnic.  Admittedly, the trails can be a little tough (many hikers that we passed had trekking poles).  However, we also saw a family with 6 kids (all under the age of 12) that handled the trail like pros.  I think it all boils down to experience.

Smiley (7) did great on the trails.  It was an excellent work out for both of us.  At the end she remarked that she “felt the burn” (meaning her muscles were burning from the exercise).  I think the steps would have been hard to navigate for the twins (3).  

If you do plan on visiting with kids, you may want to consider the Main Park Drive Loop.  Probably one of the coolest thing about the park is the suspension bridges.  One of these bridges is easily accessible at the very beginning of the trailhead.  You could easily walk across the suspension bride and then head down the neighboring steps to walk along the creek bed.