One of the reasons I 愛 OUAT is because its basically just one really screwed up family. Nearly all the main characters are related in some way at this point. While I was putting together their family 木, ツリー I thought of something that would make it even better.
All we need is for two theories to be confirmed.
Theory #1: Eva and Cora are sisters. This would explain why Cora was so familiar with eva at her funeral.
Theory #2: Gina is Rumple's illegitimate daughter with Cora, unbeknownst to him. We know Rumps and Cora were in some sort of relationship so this isn't impossible.
We know so little about Cora at this point that its quite possible that one または both of these could be true and if they were the OUAT family 木, ツリー would be come a circle.