Yes, Aatika was the name of a Sahabiyah. Also Aatika was the name of the wife of the second caliph Hadhrat Umar (رضى الله عنه). It is good name. You can keep it. However, if you like the name Fatima more (the name of the daughter of Hadhrat Muhammad صلى الله عليه وسلم), then you can keep it instead of Aatika, rather it shall be better.
Allah (Subhana Wa Ta’ala) knows Best
Darul Uloom Deoband