Born in Klisinec, Bohemia on March 21, 1864 to Frantisek (Frank) Sismilich and his wife Anna Vala, Stazie came to America as a young girl of 4 with her parents, brothers, and sisters in 1868. She did not receive much formal education, and even though she emigrated at an early age, she retained a noticeable accent her entire life.

Little is known of her early childhood. Though legend says the family lived on a farm in Haverstraw, Rockland County, NY immediately after their arrival, this has never been substantiated. By at least 1876, like many Bohemian immigrants, Stazie's family was living in the New York City ghettos on the Lower East Side of Manhattan. That year, the first pair of tragedies struck. In May, her older sister Marie, married for only a short time, died in childbirth at the age of 20. Then their mother, Anna, died just half a year later, in December. Suddenly Stazie, at the age of 12, was now the oldest woman in her family. She was said to have helped her father raise her younger sisters and brother, something which undoubtedly contributed strongly to the sense of family she exhibited in later life. Four years later, when the 1880 census was taken, Stazie was still living with her father and younger siblings in the same neighborhood. Her father Frank was a cigarmaker, and as was common in those days, particularly in the cigar industry, the children also worked in the business. Her job might have been to hand-paint the labels for the cigars. Family members have stated that she continued to work in this industry her whole life.

Around 1886, Stazie married Antonin (Tony) Stejspal (pronounced "Stay-spall"), who was six years older. In rapid succession they had three chidren: Frank in 1888, Rosalia in 1890, and Anton (Tony) in 1892. Though Stazie was born Catholic, she raised her children as Lutherans. Stazie once told the story how she had the children attend a nearby church when they were small, and since it had a cross on it, she assumed it was Catholic (apparently she was not a churchgoer herself). When the children reached the age for their Confirmations, she asked them to have the priest call on her. However, to her surprise, a minister arrived instead. Despite this mixup, she continued to have the children attend this church.

Stazie's life had been hard enough up to this time, for by all accounts the Stejspals were quite poor. But the early years of the 20th Century were even more trying for her: tragically, all three of her children would die as teenagers of 18 or 19, one after the other, between 1906 and 1911. One of the boys, who worked for the electric company in New York, was electrocuted when struck by a live wire as he was climbing a utility pole. Another child died from tuberculosis, which would spread like wildfire through the crowded tenements. A vivid memory for many of her nieces were the photographs that hung on Stazie's living room wall for years afterwards of the three children in their coffins. Finally, in 1920, even her husband Tony died. He contracted tuberculosis, probably while caring for their sick child. Stazie would constantly wear black for the rest of her life.

After Tony's death, with her whole family gone, Stazie's mind would never be far from her parents family or her own. She bought a large burial plot in Lutheran Cemetery in Middle Village, Queens, to bring all her family together. In November 1921, the remains of her parents, her sister Marie, and her own husband and children were removed to this common grave. The plot is located near the monument to yet another tragedy, that of the General Slocum, an excursion ship which took widows and children out for a day's sail on the East River. The Slocum was consumed in a tragic fire, and thousands of people were killed.

In the following years, Stazie would frequently attend seances, undoubtedly in an attempt to communicate with her deceased family members. Occasionally she would try to get other family members to go along with her. Apparently she was quite serious about the seances. On one occasion she asked her sister Josephine to go with her so that they could both contact their late husbands, but when Josephine jokingly told Stazie, "If you happen to get in touch with John, tell him the babies need shoes", she became infuriated with her sister. In later years, Stazie lived at 527 E.78th Street in NYC, near her brother Frank, and perhaps also at 579 E.79th St., too. She liked to attend the theater, but generally is remembered as a loner. She would visit the families of her brothers and sisters from time to time, invariably dressed in black. Few people looked forward to her visits. Whenever she came to visit her youngest brother John, who she undoubtedly had a large hand in raising since he was only 3 when their mother died, she always would put him in a rotten mood that would last for days afterwards.

Probably because of her role in raising her siblings and the tragic deaths of her own family, Stazie seemed to be the only Sismilich of her generation who paid attention to the family history. Her letter to a grandnephew, written during the late 1930's in the days leading up to World War II, is one of the few contemporaneous family documents to have survived to this day. She wrote it several days after visiting him and his wife, and relating for them the story of their ancestors.

Stazie developed cancer, and spent her final days in the hospital of the Cancer Institute in NYC. When a grandniece visited her just before her death in May 1941, Stazie was preoccupied with the disposition of the old-fashioned mirror in her apartment. She called two nurses to witness her signing a paper giving the grandniece authorization to take it. However, by the time she went to get it, someone had broken it all apart. The grandniece strongly suspected that Stazie kept her money and perhaps other family treasures in it. Oddly, whoever had broken up the mirror has also taken all the linens and towels from her apartment.