Gertrude Imogene Rupert was born in Fairfield, Iowa to Anna McReynolds. Although her father is listed as railroad worker R. Frederick Rupert, Frederick and Anna were not married until June of 1878 when Imogene would have been 18 months old. Either she was born to the couple out of wedlock, or her true father remains unknown. It was evident that the family was on the move. Imogene had one younger sister named Pearl (4/1882) born in Missouri, and a brother, Donald (3/31/1886), born back in Iowa.

For the 1885 Iowa census, the Rupert family was found living in Moulton, around 40 miles southwest of Fairfield. Little is known of Imogene's musical training, but it was evidently sufficient enough that she was able to find employment in the music field. At one point in the mid-1890s, Pearl and Daisy were residing in Macon, Missouri, some distance west of Hannibal, Missouri. By the time of the 1900 census Anna had died, leaving Frederick a widower, and Imogene was living on her own in Quincy, Illinois, just across the Mississippi River from Hannibal, where she would spend most of her life, listed and reference as Daisy Rupert (her preferred nickname back to childhood), and working as a music teacher. The Quincy Herald frequently ran one sentence snippets about her entertaining either in town or in some nearby hamlet in Illinois or Missouri.

In June 1901, Imogene was married to Emerson Henry Giles, who was originally from Pennsylvania. The event was announced in The Music Trade Review of July 6, 1901:

Mr. Giles, some 13 or more years older than Imogene, ran the successful Giles Brothers Music Company in Quincy, Illinois with his brother Jacob E. Giles. Reorganized with his brother in 1888 from a music store originally founded with Emerson's uncle, they sold pianos, organs, various musical instruments and sheet music, and later published some music. Many directories show them as a typewriter dealer as well. Within a couple of years of the wedding, Imogene started to teach music at the company store. Her husband was already well known by that time as somewhat of a local philanthropist.

The sometimes quirky Mrs. Giles may very well have published only one ragtime piece in addition to one other march attributed to her. Her single rag, Red Peppers, issued in 1907 by the Giles Brothers, is well crafted and leaves historians and collectors wondering what more she was capable of. The 1910 census showed her with no profession, and for whatever reason that she was now originally from Florida, where she alleged that her mother was also born (other census records indicated that Anna was from Illinois). Emerson was listed as a partner for a music house. It was known that the couple attended Central Baptist Church in Quincy, where Daisy could potentially have been involved with music ministry in some capacity, and where Emerson was on the board of directors.

Emerson started to show signs of apoplexy and in 1921 had a cerebral hemorrhage which set him back. He suffered a second one the following year. In spite of this Mr. Giles managed to recover enough from both of these to continue running his business. However, the third one was too much to endure, and he died just two days before Christmas in 1923. This was followed by more of a year of wrangling about his estate, managed by his brother Jacob. She eventually ended up with half of the remaining assets despite many challenges and bequests. The music store property went to auction in March 1925. In both the year of and the year after Emerson's death, Mrs. Giles was listed as a musician for the Star Theater, likely playing for both silent films and occasional live shows. However, she was not seen in directories after 1925, so may have used a different name. The 1930 and 1940 enumerations came up empty despite searched under multiple names. The 1950 census found her living at the St. Vincent’s home for the aged in Quincy. Little else is known of her later years, most of which were lived out in Quincy. Daisy died there at age 87 after a brief illness.