Answer
(Fatwa: 1166/675/D=1432)
According to Islamic teachings, it is forbidden to talk and see a strange girl. Her hair is included in satr covering which is fardh on her. Hence, it is not lawful to have the condition of talking and watching the hair before marriage and insisting over it. However, one who intends to marry her, it is allowable for him to see if he finds a chance seeing her or talking with her, yet it is not allowable to see the hair. It is better for you to send some female members of your family to her house in order to know about her.
Allah (Subhana Wa Ta’ala) knows Best
Darul Ifta,
Darul Uloom Deoband