In the name of Allah the most Gracious the most Merciful
The answer to your question is as it follows:
If girl agreed and got married with the person only for the sake of her mother’s happiness, the Nikah will take place. In this case, preferring mother’s happiness over her own is also worthy of reward.
And Allah knows best
Darul Ifta
Darul Uloom Waqf Deoband