1) Muslim marriage is a civil contract. The signed Nikahnama is primary, binding evidence that the husband willingly entered into the marriage at that time. 

2) If a marriage has been legally solemnized, one spouse can approach the court or the marriage registrar with the Nikahnama, witnesses, or an affidavit to register it. The husband's presence or current "will" is not required to register a past event that he legally consented to when signing the contract.

3) no need to bow down to husband pressure tactics 

If the marriage was solemnised in the presence of elders as per the provisions of Sharia Law, then the registration is a mere formality and just a document to confirm their marital status, even without the registration certificate the marriage is very much valid.

Therefore the registration of Nikahnama is just a formal confirmation of their legally valid marriage.

However, it is a question that how come she got the deed registered unilaterally without his signature in the application form as well as in the registration document, you may confirm that if she has not forged his signature in the application form because it would be an offence.