it would help if you know the source for the name. What does Elka mean? Believe it or not I am unfamiliar with the spelling of the name when written with Hebrew letters. Is it asn ayin or an aleph? Koof or kuf. Is it written like one of the “Sheimos” because if so, then it seems to derive from that, much like the girl’s name of Elisheva or Eliana. The “kah” part is typically an endearment added to many European names. The K sound is not necessarily part of the original name (as someone thought Elkonoh, which IS a male name).
A good example of this is a name like Shmuel. My friend calls her son Shmuel-kah (similar to the name Shmelkie). the K is superfluous, but added to the name out of affection. Sometimes OTHER letters in the name are dropped as the K sound is added. So Miriam can become Mirkah or Mirchkah (as I have in my own family on my husband’s side) Rochel becomes Roch-kah, etc. Perhaps the same holds true for Elka. Maybe it is a contraction of something else (and if spelled with an ayin, maybe the original name was Aliza – who knows?)
I give this a lot of thought, because naming our children after family members was a very big deal to me, and my husband and I do not believe in the usage of anything other than Loshon Kodesh for a Jewish child’s name (I am not chalilah criticizing those who use Yiddish names, but that never made sense to me any more than it would nowadays to use an English name of someone Choshuv, over Loshon Kodesh). So for example, girls who are named for a Faigel and Fraydel, would be Tzipporah and Aliza (or Gila).