Question:

What is the Shar’ee ruling of hijab from a real cha-chee (father’s brother’s wife)?

Answer:

It is permissible to marry ones cha-chee if her husband dies or she is divorced. Therefore hijab is necessary from her.

(Hazrat Shaheed Mufti Maulana) Yusuf Ludhyanwi (May Allah have mercy on him)

Aap ke Masaail aur unkaa hall Vol.8 Pg.72