The bathrooms were clean; the picnic site, shady. The trails are very well-maintained. It is family friendly for kids 4 and up, but a bit steep, with too many narrow spots near the edge of cliffs, for strollers unless you stick to the pleasant park at the bottom of the trail (we saw a couple birthday parties down there). Adults or older children with hiking experience can add more "loops" to the trail to lengthen the hike.
We saw native Californian ground squirrels (most of the ones in our neighborhood are the invasive ones originally let loose to make the parks look "wild") and a small snake. The trees kept the sun off us for most of the trip up the hillsides. The waterfall, which is supposed to be very picturesque at the right time of year, is almost dry in the summer, particularly due to current drought conditions. But the views were outstanding. The trail was busy -- it was a Sunday morning, after all -- but not too crowded, and the other hikers were friendly: lots of smiles, hellos, and no shoving to pass on tight spots of the path.
We definitely want to return.
In other trip recommendations, my friend Marion B. suggests checking out the museum at the Pacific Design Center. She takes her kids with sketchpads and drawing supplies.
Another friend, Devorah Talia G., took a great hike in Vasquez Rocks Natural Area last week. She says to pick a cool-ish day at this time of year, but the hike was not too challenging for her school-age children. Unlike Temescal Canyon, the drive out to the trailhead took a long time from her L.A. home, but she reports that it was worth it. I think we might be trying trip that sometime soon.