A:
A Muslim should not
exaggerate in the amount of Mahr; as it complicates marriage (Part No. 19; Page No. 74) and burdens people with what they may not be able to afford. The father is permitted to take from his daughter's Mahr as long as it does not entail harm on her and that she does not need it. The Prophet (peace be upon him) said,
You and your property belong to your father.
If the father takes money from his son or daughter that does not cause them harm, and which they don't need, he is allowed to dispose of it, perform Hajj from it or give Sadaqah out of it. The reason is that the money becomes the property of the father when he takes it. May Allah grant us success. May peace and blessings be upon our Prophet, his family and Companions.