In my language we generally don't distinguish genders. This includes kinship terms.
With mother & father being obvious exceptions, we don't distinguish between sister|brother, daughter|son, niece|nephew, sister-|brother-, daughter-|son-, mother-|father-in-law, girlfriend|boyfriend, fiancée|fiancé (though this last one sounds the same in English anyway), etc.
I looked up for the words for sister and brother in Finnish and found that there's sisar, sisko and veli.
So my questions are:
1) Are kinship terms in Finnish generally are also genderless?
2) Are the gender specific terms often loanwords? Assuming that sisar & sisko are loanwords from Germanic?
Thanks!
