Can a brother perform Hajj on behalf of his sister who suffers from diabetic foot disease?

It is permissible for a brother to perform Hajj on behalf of his sister if she is afflicted with an incurable illness that prevents her from performing the rituals, provided that the brother has already performed Hajj for himself and that he has her permission. However, if the sister is capable of performing Hajj herself, then it is impermissible by consensus to perform Hajj on her behalf for the obligatory Hajj. As for voluntary Hajj, it is not permissible for someone who has not performed Hajj al-Islam to appoint a proxy, whereas it is permissible for someone who has performed Hajj al-Islam and is incapacitated to appoint a proxy. However, for someone who has performed Hajj al-Islam and is capable, there are two narrations: permissibility, which is the view of Abu Hanifa, and impermissibility, which is the madhhab (definition) of Al-Shafi'i. Furthermore, it is not permissible for a brother to perform Hajj on behalf of his sister, neither obligatory nor voluntary, if he has not performed Hajj for himself, due to the hadith (definition): "Perform Hajj for yourself, then perform Hajj for Shubrumah."