Answer
(Fatwa: 683/683=M/1429)
The person who had adopted the girl is not her real father. It was wrong to mention the name of adopter in place of her real father. The Nikah becomes invalid if the name of father is taken falsely. However, if the girl was herself present in the meeting and the Nikah was performed before her in the presence of legal witnesses, then the Nikah was valid.
كما فى الدرالمختار: غلط وكيلها بالنكاح في اسم أبيها بغير حضورها لم يصح للجهالة و كذا لو غلط في اسم إلا إذا كانت حاضرة وإشار إليها الخ
Allah (Subhana Wa Ta’ala) knows Best
Darul Ifta,
Darul Uloom Deoband