Here are a few options that exist.

Creating a profile is free with an email address and a few basic details.

Through the Stir app, users can start conversations with other single parents that capture their interest.

Plenty of Fish

Plenty of Fishis a free dating site for singles worldwide.

eHarmony

eHarmonyshares several statistics on its website.

A basic membership is free.

SingleParentMeet.About single parents and dating.

App Store Preview.Stir - Single parent dating.

Plenty of Fish.About POF.

Plenty of Fish.Study: Single mothers find partners faster.