No, not from the parent's spousal petition. A valid step-relationship is only established when a child is under 18 when the parent marries.
SEE INA 101
(b) As used in titles I and II-
(1) The term "child" means an unmarried person under twenty-one years of age who is-
(B) a stepchild, whether or not born out of wedlock, provided the child had not reached the age of eighteen years at the time the marriage creating the status of stepchild occurred;
After getting LPR status (a greencard), the natural parent can file for you but there will be a long wait for a visa and you cannot file for adjustment within the U.S. unless maintaining lawful nonimmigrant status.