I'm playing four families, one is only in its first gen, two others have had one set of triplets each by the third generation, the other family has seen no triplets yet (also in its third gen) but is making up for that by having three sets of twins.

I did do a little experiment, and thought I was getting somewhere when one of my twins grew up and promptly had a set of twins himself, but then he followed that up with three singletons.

Then my control family of all single births turned around and had a set of trips themselves, just to spite me *shakes fist*.