Namesakes
Other Royalty:
2 princesses, 1 princess/empress consort
Maria Feodorovna of Russia (middle name Frederikke) 1853-1866; 1881-1894 Denmark; Russia 
Ingeborg of Denmark (middle name Frederikke) 1878-1897; 1897-1958 Denmark; Sweden
Feodora of Denmark (middle name Frederikke) 1910-1975 Denmark