Single parent and entry to Brazil

I found a similar topic on this forum but it didn't answer my questions;
I am travelling solo to Argentina with my 4 year old and we have 7h transit in Brazil ( not leaving the airport ). I read that as for Brazil I need an authorization from the other parent or a letter from the court signed by the lawyer ( probably translated as well ). Do you think its the same for transits? Does anyone have any experience? I am trying to contact the embassy, so far no luck. Would prefer to avoid unnecessary costs but on the other hand, want to make sure I won't have any problems upon arrival.