Given how episode 7 is titled "Left Behind" - the same title as the DLC which told Ellie and Riley's story - it is clear that episode will feature Storm Reid as Riley.

Source: https://screenrant.com/where-did-the-fireflies-go-last-us-episode-6/

In the DLC, Ellie (Bella Ramsey) and Riley (Storm Reid) encounter a horde of infected who ambush them.

Source: https://www.cbr.com/last-of-us-hotel-basement-hbo-show-exclusion/

'Last of Us' guest star Storm Reid on Riley-Bella relationship: 'Love is beautiful'

Source: https://www.realitytvworld.com/news/bbc-orders-season-2-of-reality-show-the-traitors-50213543.php

Storm Reid, most popularly known for her role as Gia in “Euphoria” and Meg in “A Wrinkle in Time,” is developing into an impressive actress and appears to be a star in the making.

Source: https://arbiteronline.com/2023/01/23/missing-tells-the-tale-of-a-daughter-who-will-do-anything-to-save-her-missing-mother/

This is the conflict established between Ellie (Bella Ramsey) and Riley (Storm Reid).

Source: https://www.forbes.com/sites/erikkain/2023/02/26/the-last-of-us-episode-7-recap-and-review-left-behind/

Whether Ellie is spending time at an empty mall with Riley Abel (Storm Reid) or Joel is meeting up with his brother Tommy (Gabriel Luna), every scene was shot in Alberta.

Source: https://gamerant.com/the-last-of-us-hbo-filming-locations-explained/