A petition may be filed under this chapter requesting an order setting aside the decedent’s estate to the decedent’s surviving spouse and minor children, or one or more of them, as provided in this chapter, if the net value of the decedent’s estate, over and above all liens and encumbrances at the date of death and over and above the value of any probate homestead interest set apart out of the decedent’s estate under Section 6520, does not exceed twenty thousand dollars ($20,000).