Should I mention if food isn’t Halal without being asked?

Salaam everyone! I work at a bubble tea shop and we have a big menu with drinks and snacks. A lot of Muslim sisters come by, masha’Allah. Last time, a sister asked if our donuts were Halal, and I said yes, but I mentioned the croffles have gelatin in the cream topping and might not be suitable. She didn't get mad, but I could tell she was a bit worried, and I felt awful. To avoid this in the future, is it okay to tell a sister in hijab about non-Halal items before they order? What’s the best way to say it politely? Jazakum Allahu khairan for any advice!