Shaykh Muhammad Ibn Hizaam was asked:
“One of the members of the family, his actions are evil. Thus, if the rest of the family speak in regards to their brothers, is that considered backbiting? It may be the nephew or cousin or similar to that.”
“If they speak amongst themselves to correct the situation or to aid each other upon advising and getting rid of this evil, then it doesn’t enter into back biting if Allah wills.
But if there is no benefit in it, rather the speech is without any legislative intent, then it enters into backbiting the prophet صلى الله عليه و سلم said:
أَتَدْرُونَ مَا الْغِيبَةُ ” . قَالُوا اللَّهُ وَرَسُولُهُ أَعْلَمُ . قَالَ ” ذِكْرُكَ أَخَاكَ بِمَا يَكْرَهُ
Do you know what is backbiting? They (the Companions) said: Allah and His Messenger know best. Thereupon he (the Holy Prophet) said: Backbiting implies your talking about your brother in a manner which he does not like.
As for the one that intends to advise or correct, then he doesn’t enter into that.
Majid Jawed Al-Afghanee