A form of the name is the English Jonika.
Jonica is not often used as a baby girl name. It is not in the top 1000 names.
Baby names that sound like Jonica include Jonika, Jaakina, Jaakkina, Jachana, Jachanna, Jacinna, Jacqueena, Jacquena, Jahana, Jahanna, Jahnaya, Jakeama, Jakeima, Jakima, Jakina, Jakkina, Jakyma, Jakyna, Jamaeca, and Jamaeka.
† Pronunciation for Jonica: JH as in "joy (JH.OY)" ; OW as in "oak (OW.K)" ; N as in "knee (N.IY)" ; IY as in "eat (IY.T)" ; K as in "key (K.IY)" ; AA as in "odd (AA.D)"