When did Shivangi learn about Ruchika/Sesha beinng her Aunt?

When and how did Shivangi learn about Ruchika's real identity as her Aunt plus how did she suddenly learn that Yamini is her great Aunt or Rithik's Aunt? Is this a blooper or did i miss out something because in yesterday's episode Shivangi was trying to find out about the relationship between Yamini and Rithik and today she suddenly tells Rudra that both Sesha and Yamini are her Aunts.

She knew about sesha already...but she didnt know abt yamini being ritik's aunt...missd yesterday's episode so i hope there is clue to her in that episode...