Where does “Marnie” come from?

Marnie is a feminine name derived from English Marian, which comes from French Marie, ultimately from Latin Maria combined with the masculine suffix -anus.

Ancestry of “Marnie”, step by step

Step	Language	Word	Meaning
1	Polish	-ie	forms adverbs from adjectives
2	Old Polish	-ie	forms adverbs from adjectives
3	Proto-Slavic	-ę	Forms nouns for young animals and other...
4	Proto-Indo-European	-ę	—

Every word from Proto-Indo-European -ę →Every word from Polish -ie →Every word from Old Polish -ie →