I'm not sure which way you're going with this, but the Philadelphia Museum of Art, down the street from the Franklin Institute, isn't specifically geared towards adults and has lots of programming specifically for kids. Seeing Rubens' Prometheus Bound there as a child as part of such a program left me in awe. I remember the feeling to this day. Every time I go, I see families with young children or even just groups of teens there.

The Philadelphia Zoo also has events planned specifically for adults. My girlfriend and I went to one a few months ago. I'm not sure what specifically about the Philadelphia zoo, the Bronx zoo, the Shedd aquarium, etc. is for specifically geared towards kids, though.