Wait, if you decided to go with Elis for her name as per the Authors clarification, why do the info boxes on pages 7 and 45 still say Alice for her first name?
I will say that this is pretty much entirely the artists fault, since he seems to want to constantly focus the story on progressing all the side couples while never really sparing much time to have Youki actually interact with Cecilia in any significant manner. And any time Youki does get time...
You have to remember, in her world the most common fish is apparently incredibly unpleasant, so she likely avoided eating it as much as she could. Which means she likely has no real experience with eating fish to begin with, adding onto the fact that something like salmon is very unfamiliar to her.
Still don't understand why all the mothers have Japanese names when almost nobody else does, not even the MC who's actually an isekai'd Japanese person.
I'm actually kind of surprised the sister didn't cause a scene over this, considering she spoke so confidently about how it was herself that was going to be the next head of the family, in front of all the guests, just before this.