She doesnt remember because Oscar turned back time/asked the angel for the memories of his past life in which ( ines's real first life) she was married to Carcel, and they loved each other very very much.

Oscar was jelous and wanted Ines then, so he retained his memories and turned the time. He stole Ines from Carcel in her second life( the life where she marries the Crown Prince Oscar) but Ines believes that that is her first life. Thats also the reason why Oscar Rapes Ines every time after he sees that Ines amd Carcel exchanged a few words. 

Later after she meets a priest, falshbacks of her real first life will be revealed to her, because she "chose right" this time. And so she'll see that truly, Carcel has always loved her, in each and every timeline, Carcel loved her deeply