I regularly attend conferences with my colleague (who I don't know particularly well), there is usually a couple of us who go and we always visit a particular restaurant afterwards. Said colleague often moans (don't blame her) that there is limited things she can eat on the menu because the meat isn't halal and she can't eat anything that anything that's cooked in alcohol, therefore she always orders a particular fish dish from the menu (there are other options).
So, we went for the meal yesterday and I fancied having the fish dish myself (it was very naice) and notably said in the description that it was cooked in gin. I have this morning realised that my colleague has been eating a dish cooked in alcohol that's against her religion 
surely she has noticed in the 5+ times she's eaten it as it's clearly stated on the menu?
I should tell her, I know I should, but I don't want to really upset her or make her feel like she's done wrong in her religion and given it's just me and her and a four hour train ride this afternoon I don't know if I can face it. AIBU?