This discussion will be appearing in the Gazette next month, but I wanted to start compiling notes now (while my brain is trying to wrestle with ERISA law concepts during lunch).
Cera was the name of at least three Irish saints who lived prior to c. 1200 CE. It is registerable as a pre-1200 spelling of the name. The post-1200 spelling is Ceara, which is also registerable as a saint's name.
Ciar is another female Gaelic name with a similar sound, also the name of a saint appearing prior to c. 1200 in Ireland.
Kira is found as a female given name in Russian, dated to c. 1202. "Russian Names Database" by Paul Wickenden of Thanet (http://heraldry.sca.org/names/paul/ka.html)
Kyrra Sranis; Female; Marriage; 02 Jan 1629; Evangelisch, Schotten, Oberhessen, Hesse-Darmstadt; Batch: M92548-1
NCMJ (1999) lists Kira as a historical surname dated to 1332.
Using surname as given name:
Burial Date: 24 Dec 1585
Burial Place: Cranbrook
Indexing Project (Batch) Number: B02880-3
Name: Richard T...Herst
Spouse's Name: Mergery Keyre
Event Date: 13 Aug 1576
Event Place: Cranbrook, Kent, England
Indexing Project (Batch) Number: M01834-4