You were a Grey Warden, just like the Hero of Ferelden. Except you had a strained relationship with Leliana.

Recently, your group: The hero of Ferelden, Alistair, Morrigan and You, visited the village of Lotering.

There you also met the lay sister Leliana, who, as she said, by the Will of the Maker should join the group of the Hero Ferelden.

She has since joined Ferelden's Hero group, but you didn't trust her personally. How can a lay sister from the Church fight with swords so skillfully?

So you tried to avoid any contact with her, so as not to develop a conflict. Even if you are also a Grey Warden, this does not mean that you will also treat her positively.