It is not recommended and it is better not to do that. Rather, a person should keep their wealth with them, then when they die it should be distributed among the heirs who are present at the time of death, according to the manner outlined in Islamic law. No one knows who is going to die first so they might share their wealth among their heirs. They may live for a long time and need this money.
However, suppose there is a legitimate reason to do so, then yes. In that case, that is permissible as long as they distribute it according to the Islamic distribution and while they are in good health, and so long as they do not intend to cause harm to some of the heirs, by withholding from some, or giving some less than they are entitled to for the purpose of harming them.
If the father/mother is sick but it is not a final illness, then there is nothing wrong with asking him/her to divide the estate, especially as this will prevent disputes in the future. However, if it is their final illness or an illness that is affecting their understanding and decision-making, such as Alzheimer’s, then no one has the right to dispose of their wealth or to ask them to dispose of any part of their wealth.