Answer:
(Fatwa: 1829/270=B/1429)
The face, hands and feet of a woman are not satr (coverable) but it is necessary to cover them if there is fear of fitna (mischief/evil). It is allowable if you keep your eyes lower, explain to her and help her in her work. You can also see her face when there are necessary questions and answers, but it also should be avoided unless necessary. If there are men in the party, you can go there to attend the party. You should lower your eyes as much as you can, but it is better to avoid accepting parties of women.
Allah (Subhana Wa Ta’ala) knows Best
Darul Ifta,
Darul Uloom Deoband
