Monica and Steve have two kids. As they weren't referred to as "twins", I'm going to assume that they're not. Assuming Monica got pregnant on the first date and again immediately after she gave birth (which is perfectly possible, but an unusual choice and very strenuous on the mother) that puts the episode 18 months ago, no later than July 2013.

Considering that Tinder was launched around August 2012 and assuming Monica and Steve are modern and responsible people (ie. are careful not to rush into the big responsibility of parenthood), I'd say it's highly unlikely.