Assalamalaikum, Is it permissible in Islam for a father to give his property to his daughter after marriage without giving to her husband, as he afraid of her future as her husband doesn't provide her well?

All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.

If the father has children other than that daughter, then he does not have the right to give her all his possessions, because he is Islamically required to be fair between the children, males and females, when gifting them. The Prophet said: “Fear Allah and observe justice among your children.” [Al-Bukhari and Muslim]

However, he may spend on her because of her poverty if her husband does not spend on her.

In case he does not have children other than her, then there is no sin on him giving her whatever he wants as long as he is not in a life-threatening disease. If he was in a life-threatening disease, then the gift in this kind of disease is considered a will, and the will to the heir is prohibited in Islam.

Allah knows best.