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Dictionary of Medieval Names
from European Sources

Frederica f. Fem. of Frederick.

Withycombe s.n. Frederica says that this name wasn't used in England until the 19th C, but this is not the case.

England
English
1543 Frederick StAnthonlin p. 4
Preview. DO NOT cite as: S.L. Uckelman. "Frederica". In S.L. Uckelman, ed. The Dictionary of Medieval Names from European Sources, Edition 2015, no. 1. http://dmnes.org/2015/1/name/Frederica.