Can I force my sister to put on hijab

All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad () is His slave and Messenger.

May Allah reward you for your Gheerah (protective jealousy) and eagerness for your sister to wear hijab, and we ask Allah the Almighty to grant her success in doing so.

First: We advise you to make Du’a (offer supplication) for her, for Allah the Almighty is the Hearer and Answerer. He the Almighty says (what means): {And when My servants ask you, [O Muhammad], concerning Me - indeed I am near. I respond to the invocation of the supplicant when he calls upon Me. So let them respond to Me [by obedience] and believe in Me that they may be [rightly] guided.} [Quran 2:186]

Second: Advise her gently and encourage her to wear hijab and explain to her that Allah the Almighty has made it obligatory on the women of the believers and explain to her its virtues and that it is a symbol of chastity in addition to the fact that it pleases Allah the Almighty and avoids the reasons that incur His wrath.

Third: If she responds, praise be to Allah, and if she does not respond, then it is permissible for you to abandon her if you hope that abandoning her will benefit her, but if you fear that it will increase in stubbornness, then it is better not to abandon her but to continue advising her.

As for forcing her to wear hijab, that is not up to you. Rather, that is up to your father if he is present. If he is not present due to his death, for example, then you must force her to wear hijab if you can do so and are not afraid that it will cause greater harm. The scholars have stated that a brother must prevent his sister from evil and protect her from corruption.

Allah knows best.