What do y'all think about this?

My sister blames my 13 year old niece for old men staring at her body and I find that to be messed up. My niece has bigger boobs (like every woman in my family) and so when she wears tank tops they show. Well my sister and niece went out earlier and my niece told her when they got home that the old man was staring at her and it made her uncomfortable because he was staring and smiling at her like a creep and my sister said well if you weren't dressed half naked he wouldn't have been staring at you (she was wearing a black tank shirt and shorts) and then my sister said if you plan on dressing like that you better get used to it (btw my mom was just agreeing along)... I was like y'all are really blaming a 13 year old for an old man being disgusted and they were like yes we are.. My sister said she wouldn't say anything to him because my niece is basically asking for it and that she might say something if my niece was fully covered.. We live in Florida and it's 🥵.. I was quite shocked by what they said.. Maybe I'm over reacting? If I saw an old man staring at my child I would definitely say something no matter how they were dressed!