In season 1 episode 9 Kovacs gives Mary Lou's stack to his sister Rei while faking his apathy for all of it.
Mary Lou's stack was taken by Ortega much earlier in the series, and Ortega is now already with Rei being tortured.
When did the exchange between Ortega and Kovacs take place? I must have missed it.
Two pages on Wikia and an article were not helpful: