The folkloric show is offered as a shore excurion on most cruise lines. How old are your kids? My daughter was around 6 years old when she went and enjoyed it.
I do NOT suggest taking kids to Tulum -- it's a VERY long, hot day and the kids will whine too much. One of the times we called in Cozumel, my husband did something w/my daughter and I went to Tulum on a shore excursion alone. Good call -- I enjoyed it but some older folks passed out from the heat/long day!