Please note that the gravestone is wrong on her first name and her date of birth.

Correct name: Antonina
Correct date of birth: January 17, 1866

Her death certificate recorded a birth date of February 18, 1866. This date is different from that on the gravestone. Both dates are incorrect. The date on the death certificate was the closer of the two. Research in December 2020 found the baptism record in the digitized parish records for Brodnica, Poland, [available in FamilySearch] following the discovery of a marriage record for her parents (at Brodnica in October 1864).

Transcription of her baptism record:
Antonina Zakrzewska, born in Zmijewo on the 17th January, 1866, christened on the 21st January, 1866, daughter of Franz Zakrzewski and Marianna Zagorska. Godparents: Franz Rozalski and Marianna Borkowska. [baptism register of Brodnica parish; entry 14 for 1866]

Her name was most commonly spelled Antonina in U. S. records. That name appears in 9 of 12 baptisms of her children--John in 1884; Veronica in 1885; Sophia in 1888; Peter in 1890; Joseph in 1892; Pelagia/Pauline in 1893; Ignatius in 1895; Maryanna/Marie Louise in 1896; and Tekla in 1906).
Second most common spelling was Antonia--found in the baptism records of children (Stanley in 1899; Sylvester in 1900 and Angeline in 1902; 1900 and 1920 censuses; probate file from 1928); other instances: Antony (1910 census); Antoinette (1927 obituary); Antoninam (1883 marriage record); and Anthominne (baptism of Frances in 1898)

Marriage records:
The 1883 Howard County marriage record for Antonina does not record her mother's name. Her father's name is given as Franz. The parish record of the same 1883 marriage named Antonina's parents: Francisci et Antoninae Antoszewska. [St. Anthony parish marriage records, Farwell (Nowy Poznan); p. 11] The 1883 marriage record is incorrect for the name of Antonina's mother. Her mother's name should have been Zagorski. Antoszewska would have been the maiden name of Frank's second wife, not his first (the mother of Antonina and her brother Wladyslaw).

Her mother, Marianna (Zagorska) Zakrzewski, died in 1870.