The Irish given name Úna was "anglicized" in various forms (i.e., made to seem more "normal" to English speakers), including Unity, Winifred, Agnes, and even Juno. It is not uncommon to find the same person with his/her name anglicized in various ways over time in different records, especially if the person lived in an area where most people were still speaking Irish at the time of baptism, and may not have spoken much English. Priests and officials often took it upon themselves to record a given name of their own choice when making out a record, which the person involved (or the child's parents) may not even have realized, especially if they were illiterate. I have a 2x-great grandfather whose name was Tadhg, whose parents probably spoke no English, and who was recorded as Thomas, Timotheus/Timothy, Thaddeus, and Thady in various records over his lifetime. He ended up as Thady in later years, and that name was used in subsequent generations.
Some priests chose to use a Latinate form or a Biblical name which seemed appropriate, while others chose a "normal" English name which appeared to be similar. The Latinate/Biblical forms were often replaced later with more anglicized forms, but some of them "stuck". A boy called Donncha by his family might be recorded as Dionysius by the priest, but that was usually anglicized later as Denis. A boy called Conor by his family often became Cornelius in the parish register, and that was considered acceptable as an anglicized form, and became popular in some families.
Most people eventually came to use just one particular anglicized form, but they might later choose a different one, especially when emigrating. So, a Máire who had been recorded in her baptismal record with the Latinate form Maria was usually later called Mary, but might have chosen to become Margaret when she emigrated, just because she preferred that name. I have a great aunt whose baptismal name was Bridget (though called Bríd at home) who later became Beatrice and then, once in the US, became Sheila!
