Her colleague called her and asked her to sign in for her when she was late, without the knowledge of their boss
Question

Sometimes one of my work colleagues calls me and asks me to sign in for her, due to some emergency that has arisen, and it is possible that she will be late or will not come at all, and the boss at work does not know about this. Please note that she tells me that she will be late and that she will not be absent. Is there any sin on me if I do that?
Praise be to Allah.It is not permissible for an employee or student to sign in for a colleague or classmate, because of what that involves of lying and deceiving the boss or the school or teacher, and because it comes under the heading of consuming people’s wealth unlawfully if the person will be paid for this work for which he or she will be late.
You should not be so easy-going with your colleague in this matter, for you are committing a sin and helping her to do something that is haraam, and you are participating in cheating, deceiving and betraying a trust.
It makes no difference whether she tells you that she will be late or that she will be absent. No one has the right to sign in on behalf of anyone else. She has to tell the boss that she will be late or absent, and she should beware of consuming wealth unlawfully, because the Prophet (blessings and peace of Allah be upon him) said: “Every body that is nourished with haram wealth, the Fire is more befitting for it.” Narrated by at-Tabarani from Abu Bakr; it was classed as saheeh by al-Albani in Sahih al-Jami‘ (4519).
It is unfortunate that this phenomenon is widespread among many Muslims nowadays, despite what it involves of blatant lying and deceit. Hence the ruling that it is haram should be broadcast widely, along with the warning against taking people’s wealth unlawfully.
We ask Allah to help us all to do that which He loves and is pleased with.
And Allah knows best.