(a) If the decedent leaves minor children by different spouses, the probate court shall specify the portion going to the children of the former spouse or spouses, which portion shall vest in those children.

(b) If the decedent leaves minor children and the surviving spouse is the parent of the minor children, the probate court may in its discretion specify separate portions for the minor children and the surviving spouse if the court deems the award of separate portions to be in the best interests of the parties, and the portions shall vest separately in the surviving spouse and the children.