As I just said in another thread, I'm not surprised about the reveal. I knew instantly when the solicits said Elektra would drop a bombshell of a secret that it would be that Elektra had a child. I can only assume that It's "Daredevil's" because considering how Elektra didn't know Matt was DD, she must of had sex with him while he was wearing the mask. Which is why she assumed DD has the child. That's just my theory though.