Tbh, considering Eteri's track record (callin Yulia and Adian lazy and spoiled, now saying Zhenya is childish after calling her her most mature student for years) I think you can very well hope it isn't true
EDIT: even if she had said that in a moment where she was distraught and crying, I think holding it against her and telling literally everyone a detail of a private conversation is still terrible. How many times have I complained to my mom about my sister in a moment of weakness? My mom would never tell my sister or the rest of my relatives because she knows they are words said in the heat of the moment. What matters is that I love my sister and cheer her on daily.