The other day, I was in some kind of park where children had tools and material to build huts. Since they weren't a lot of material, when a hut was finished it was then dismantled and the material was then used to make another hut.
My little cousins (my aunt grandchildren) started to build a big hut while my aunt and I were watching them. I was at one "corner" of the hut while my aunt was at another one, so we weren't really near each other (but not that far away either).
At some point, another child came in and started taking material from "our" hut (probably thinking that it was an abandoned hut). So, my aunt quickly told him in a "warning" voice "Oy, Oy!" to get his attention and then in a more neutral but still "schooling" voice:
This hut is being built, maybe you could take material from another one?
I'm really not sure about what her exact words were, I just recall the global intent. Plus, all this was in French so the translation might be poor.
The mother of the child was near and had heard the exchange. I believe she misunderstood the "warning" voice and took it for aggression. In any case, she became aggressive herself and started to angrily tell my aunt that this was no way to talk to a child, and that being aggressive toward a child was really unacceptable (and so on and so on).
My aunt tried to explain herself at first (in a neutral but a bit apologetic voice); but then dropped it and just let the other woman talk until she was finally over.
Since I was near, I heard the entire exchange. I wanted to support my aunt but didn't want to escalate the situation either, so I stayed back and just watched things from afar.
When the exchange was finally over, I didn't know what to do. My aunt seemed not to realize I had heard all of the exchange, and I didn't know how to comfort/support her (she seemed a little shaken by the exchange but not too much).
In this situation, how could I have been supportive of my aunt (during or after the exchange) without taking the risk of aggravating the situation when the exchange was still going on? And, if I do not intervene during the exchange, how can I still be supportive while justifying that I chose to not do anything?