Is the questioner sinful if she does not go beyond the صف (row) to alert the female worshippers that part of their hair or the back of their necks is uncovered, knowing that the سترَة الإمامة (imam's sutrah) suffices them, but she fears distracting them?

If a small part of a praying woman's hair or neck becomes uncovered unintentionally, her prayer is not invalidated. However, if the uncovered part is more than a small amount, she must be alerted verbally, for example, by saying to her: "Something from your body or hair has become uncovered." If it is difficult to make her hear, she should be informed even if it means passing in front of the female worshippers, because the Imam's sutrah (barrier) serves as a sutrah for those behind him.