One of the main requirements of Section 125 of the Cr.P.C. for grant of maintenance to wife is that she is unable to maintain herself.
Further, Section 127 of the Cr.P.C. provides for alternation in maintenance allowance, on proof of a change in the circumstances of any person, receiving, under Section 125 a monthly allowance for the maintenance. This section also allows the Magistrate to cancel the maintenance order in appropriate circumstances
In view of these, you can file an application before the court under Section 127 Cr.P.C. for alteration or cancellation of the maintenance to your wife, giving the reason of her fresh employment. The court will decide the case on merits.
To reply to the second part of your question, as per Section 6 of the Hindu Minority and Guardianship Act, 1956, father is the first natural guardian of minor son and unmarried daughter. You can file an application under the Guardians and Wards Act, 1890, for being appointed guardian and for seeking custody of your minor daughter. It will be decided by the court on merits by taking into consideration all aspects, including welfare of the minor daughter.
Dr. Ashok Dhamija is a New Delhi based Supreme Court Advocate and author of law books. Read more about him by clicking here. List of his Forum Replies. List of his other articles. List of his Quora Answers. List of his YouTube Videos.