I am presuming that Katalin is the widow who immigrated with daughter Agnes in 1914 to her son Anton in South Bend. The manifest states her age as 53.
She was from Páli, a large village in Sopron megye (county). Roman Catholic records are available through LDS for Páli, 1690-1895, and civil records 1895-1911. You should be able to find her there and trace the family back.
Since she was a widow, you will need to find her marriage record to identify her birth name.
The death records for Indiana show a Katherine Kovacs who died October 3, 1916, in South Bend, age 49. The age is not right, but this is still a possibility, since you cannot rely on stated ages either on the manifest or in the death record. Only by finding her birth record in Páli could you verify her date of birth.
If this Katherine turns out not to be your Katalin, there is a possibility that she returned to Hungary.