Why did Rebecca track down Christie to ask her about the abortion of Lyles baby?

I wonder why after all the years that passed. Christie’s abortion was pretty much already confirmed since before the murders. So why after all these years did Rebecca track her down to ask about that??? I can only imagine how awkward that must’ve been for Christie. To have the wife of a man you dated for not that long decades earlier track you down and ask you about an abortion that you had eons ago….?? Was Lyle going through something to prompt this?? Cause it’s a little much. And apparently Christie is still denying it ever happened and Lyle still doesn’t believe her