Here the is the Maryland "intestate succession" statute --- meaning the parent dies without a will -- in Maryland. If the "new wife" was legally married to your father at the time of your father's death, she is considered the "surviving spouse" for purposes of the statute below. I recommend hiring a Maryland estate and trust attorney to discuss the specifics of your situation in more detail.
§ 3-102. Share of surviving spouse.
(a) General.- The share of a surviving spouse shall be as provided in this section.
(b) Surviving minor child.- If there is a surviving minor child, the share shall be one-half.
(c) No surviving minor child, but surviving issue.- If there is no surviving minor child, but there is surviving issue, the share shall be the first $15,000 plus one-half of the residue.
(d) No surviving issue, but surviving parent.- If there is no surviving issue but a surviving parent, the share shall be the first $15,000 plus one-half of the residue.
(e) No surviving issue or parent.- If there is no surviving issue or parent, the share shall be the whole estate.
(f) Calculation of net estate.- For the purposes of this section, the net estate shall be calculated without a deduction for the tax as defined in § 7-308 of the Tax-General Article.
Best of luck.******The above is for informational purposes only and does not create an attorney-client relationship.*******