Is it wrong to let a muslim friend try a marginally alcoholic probiotic?

I have a friend who is originally from a repressive Middle-Eastern country. She is in her twenties and a moderate Muslim and lover of democracy (which is why she isn't there anymore). She has the most beautiful long wavy hair.

I was getting us some tea in the kitchen and she saw my water kefir and asked what it was. I told her that it is a fermented drink and probiotic that I drink every day because it helps me with bloating and gas and makes it more comfortable to drink milk. She said she had noticed that I seemed healthier than when she last saw me and that I had lost weight. I said to her that the beverage is very slightly alcoholic - about 1% volume - because of the fermentation process.

She then asked if she could have some.

I was delighted that she wanted to try my special drink and that she could afford herself this freedom despite being a Muslim, because I know that Muslims don't normally drink alcohol. But then I wondered: did she just not know that she was not allowed to drink alcohol under her religion and was it bad of me not to tell her?

If I was a Muslim I would have said "hey, don't you know that alcoholic beverages are haram (unclean)?". But I am not a Muslim and I do not believe that alcohol is in itself sinful. I'm the kind of Christian who believes that anything you eat or drink is fine as long as it doesn't lead you to cause harm or needlessly torture someone else's conscience or give out an inaccurate impression of who you are.

Then again, I don't know how she follows her faith (apart from being a moderate Shi'a Muslim) or whether she feels ambivalent about it. For the record it wasn't just the kefir she wanted to try: she was determined to try British tea with milk and the Italian-style gnocchi I had prepared for the both of us. She was absolutely scintillated by everything that seemed different.

Was what I did bad?