Praise be to Allah.
We appreciate your getting in touch with us, and we ask Allaah to guide us and protect us from the evil of our own selves.
With regard to your sister’s situation, it is the same in the case of many young people these days. We ask Allaah to guide them and us. Our duty towards them – as it seems to be – is as follows:
Firstly: we should turn to Allaah and ask Him to guide them, for He is the controller of the hearts. Perhaps a du’aa (supplication) from the heart will be the cause of her happiness in this world and in the Hereafter.
Secondly: you should stop dealing with her on the basis that she is a child or that she does not know what is in her best interests. People – especially in adolescence – like the people around them to make them feel that they are important; they do not like people to treat them as if they are still children.
Thirdly: try to get her in touch with righteous young women, and keep her away from her friends who are not good, even if that means changing her school. That should be done without her realizing what is going on, because otherwise she may become more stubborn which will make the problem worse.
Fourthly: You should not look at her with disapproval only, rather you should express your approval of good things that she does and you should give her gifts if she does good things.
Fifthly: you could advise her via a person whom she likes, such as a teacher or friend, etc.
Sixthly: You should try to give her audio materials or books containing teachings in an indirect manner, such as putting them near her or listening to the audio in the car whilst she is riding in it.
With regard to her not praying, this is an extremely serious matter. The status of prayer in Islam is that of a foundation on which the entire structure rests. Hence the Prophet (peace and blessings of Allaah be upon him) said, “The covenant that stands between us and them is prayer; whoever does not pray is a kaafir (disbeliever).” (Narrated by al-Tirmidhi, 2621; classed as saheeh by al-Albaani in Saheeh al-Tirmidhi, 2113)
And he (peace and blessings of Allaah be upon him) said: “Between a man and shirk (polytheism) and kufr stands his giving up prayer.” (Narrated by Muslim, 82).
So you have to advise her and preach to her and guide her to the right way; for this purpose you may combine encouragement and threat, gentleness and strictness; if the matter requires some harshness sometimes, there is nothing wrong with using it.
The Prophet (peace and blessings of Allaah be upon him) said: “Teach your children to pray when they are seven years old, and hit them (lightly) if they do not pray when they are ten, and separate them in their beds.” (Narrated by Abu Dawood, 495; classed as saheeh by al-Albaani in Saheeh Abi Dawood, 466.
This strictness and harshness is only in her best interests.
We ask Allaah to set the affairs of the Muslims straight.