Having children has made me more concerned about issues of safety, and protection from criminals is part of that.
The GSS (2008) asked respondents if the courts are too easy on criminals. 62.1% of non-parents think so; 71.4% of parents do (sample size = 1452, whites only). The difference is statistically significant.
I suspected that having a daughter might have an additional effect, but I didn't find a difference.