Hello Kamal.
One of the grounds for annulment of the marriage is that the marriage has occurred through fraud or force and without the consent of both the individuals to the marriage. Such marriages are voidable. If the consent of the complaining party has been obtained by force or by fraud relating to the nature of the ceremony performed or to any significant factor circumstance concerning the opposing party, the marriage can be voided.
However, a petition for annulment in such a case must be presented within one year after the force ceased to operate or the fraud has been discovered. Also, the petition for annulment of the marriage has to be filed by one of the parties to the marriage and it cannot be field by a third party.
Therefore, in the scenario that you have given, A does not have the legal standing in the conjugal affairs of the girl and B. However, the girl can approach the Court by filing for an annulment of the marriage on the ground so f it being a forced marriage without her consent.
-Regards
Advocate Pooja
www.lawkonect.com