Can't play multiplayer with friend

My sister just bought the physical copy of Mass Effect Trilogy for pc and installed it + all of the free DLC (including the multiplayer content) through Origin. I myself have only Mass Effect 3 (= bought separately, not in the trilogy pack) + all of the DLC. We tried to join each other in multiplayer in private matches and both got a pop-up each time telling us that we don't have the same game (?) and should purchase it first to play. I'm not sure of the exact wording in English because my Origin is in different language atm. But in short, it claims that we we don't own the same game and therefore aren't allowed to play? My sister's Origin shows that I own the ME3 game where you hover over the cover image ("friends that play" or whatever it is in English), mine doesn't show her having it, if that possibly has something to do with it.

We SHOULD have the same game version, and we both did the installation fix and update check; all a-ok. At the moment I am re-installing my copy of the fame through Origin but it still doesn't show that my sister owns the game too as it probably should. Not sure if there's any other info I should provide but please if anyone could shed some light on this issue? Thanks.