Answer
(Fatwa: 1092/633/D=1432)
What does the husband say in this matter? You should have written his statement as well. However, if it is proved according to Shariah (by two male witnesses), that two witnesses were not present at the time of nikah or one male and two females, then the nikah was invalid. Such invalid and null nikah will come to an end if husband gives one talaq; hence she can marry somewhere else after passing the iddah. This ruling is when both the husband and wife have done intercourse. And if no intercourse was done then there is no need to sit in iddah. She can do nikah without passing iddah period.
ويجب مهر المثل في نكاح فاسد وهوالذي فقد شرطا من شرائط الصحة كشهود ، وثبت لكل واحد منهما فسخه ولو بغير محضر عن صاحبه …. وتجب العدة من وقت التفريق (در مع الرد زكريا: 4/275)
وتجب العدة بعد الوطء لا الخلوة أي لا تجب بعد الخلوة المجردة عن وطء ، ووجوب العدة بعد الخلوة ولو فاسدة انما هو في النكاح الصحيح (در مع الرد ، زكريا : 4/276)
Allah (Subhana Wa Ta’ala) knows Best
Darul Ifta,
Darul Uloom Deoband