If you're physically fit and willing to carry small children and leave the oldest ones behind; this is a great hike!! Some of the switch backs are steep.
Buy the pass, support the parks, and pay for parking! There is parking up top, but lots of people don't want to pay, so they park along the rode leading up the trail head.
Seriously, you can make it to the top of the falls, but it requires effort and a can-do attitude! It's really worth it. Bring snacks to treat yourself at the top and plenty of water. We are two adults with 2 pre-teens and we all did well but rested at each level, snacked a bit, and moved on. It's a great hike during the heat of the day too!
I remember hiking this trail in the late 80's and I was in bad shape, I never made it to the top. Don't feel bad if you can't make it; try again when you are ready!!