I mean, one would usually think they'd need to be able to convey the wish in her language so you can actually get a wish (like Porunga)...but apparently she just gives whatever the other person desires AND says out loud at the moment.A bit out of character for the "genius" witch to waste her wish, but if anyone else had done that we'd resent them, so...
It's even worse if you do it as Komugi-chan!