can a person give money to his mother for her qurbani
Qurbani is not considered Zakah. It is permissible to offer Qurbani on behalf of one's mother, father or other relatives. It is also permissible to give them money so they can offer it on their own.
If someone want's to offer Qurbani on behalf of another living person then it is necessary to seek their approval.
And Allah knows best.
Mufti Ikram ul Haq