Siri will only repeat explicit language via text if you use explicit language. The digital voice assitant doesn't verbally repeat any bad words and will normally scolds users for using such language. You can stop Siri from spelling out curse words when spoken to her and stop her searching Wikipedia, Bing and Twitter by following the instructions below.
Just like with explicit music and R-rated movies you can block television shows rated TV-Y to TV-MA on any iOS devices. Here's how:
Apple allows parents to control what movies a child can download from iTunes based on MPAA ratings. For example, you can enable any iOS device to block NC-17 or R-rated movies. Here's how to restrict NC-17, R, PG-13 movies on your child's iPhone, iPod touch or iPad.
Here's how to limit adult content or only allow access to specific websites on your mobile browser:
