This is just my opinion, but I think it would be very out of place for you to give missal to people you don’t know. Maybe the woman that is wearing a skirt that barely covers her knees when she stands, let alone sits, is a baalas teshuva that is wearing a skirt for the first time, after overcoming much insecurity. Imagine what she’d feel like if you would walk up to her and say, “excuse me, I’m saying this only cuz I care abt your olam Habah- your skirt is really too short. It’s inappropriate! You are causing so many men to sin!”
Talk abt a chilul Hashem….