I am requesting an urgent response from you with regards to this matter.
My uncle passed away a few days ago, May Allaah have mercy on him. He was married three times (divorcing in between).
The first marriage was to a Canadian and he had a girl then a boy from her. I am unsure as to their religion.
The second marriage was to another Canadian Christian, and had another girl and boy from her. Since my uncle and aunt divorced, she has been raising the children as Christians.
The third marriage was to a Muslim woman who has 3 of her own children, however no children with my uncle.
My uncle has left only a small boat and a van. He asked my aunt to give these two items to two specific people should something ever happen to him. He also has a business which will be managed now by my husband to ensure his wife is well taken care of.
My questions are:
1. Are non-Muslim children entitled to any part of his inheritance?
2. Can his wife give away the boat and the van as he requested, or are his children entitled to a share of it?
3. How will the monthly income from his business be divided among his wife and children?
My uncle has been forgiven by all of any debts he may have incurred from them.

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.

Your uncle's Christian children have no right to inherit their dead father. The Prophet said: "A Muslim does not inherit a non-Muslim and a non-Muslim does not inherit a Muslim." [Al-Bukhari and Muslim] As regards the will he made on the boat and the van, then there is no harm in giving them to the people he appointed if they constitute a third or less than a third of the inheritance. However, if they are beyond a third of the inheritance, his will cannot be fulfilled, unless the other heirs [in this case the Muslim heirs only] permit it if they are mature and have a sound judgement, otherwise the share of the heir who permitted it, can be given away, and the share of the heir who did not permit it, cannot be given away.

As regards his monthly income from his business, it will be divided according to the share of his Muslim wife and his Muslim children, he himself fathered. His wife will get one-eighth of the inheritance because of the presence of other heirs.

Allaah Says (which means): {But if you leave a child, then for them [i.e. the wives] is an eighth of what you leave.}[Quran 4:12].

The rest will be divided on the sons and daughters, provided he is their father, [and provided they are Muslims] for a male a portion equal to that of two females. Allaah Says (which means): {Allaah instructs you concerning your children [i.e. their portions of inheritance]: for the male, what is equal to the share of two females.}[Quran 4:11]. However, if the heirs agree on another division other than what is mentioned above, they are permitted to do so [provided they all agree on it] and provided they are mature and have sound judgement.

Allaah Knows best.