Thanks for the words of empathy and comfort. Our choir leader, who is very skilled, will eventually deal with this. I suppose the best way is to figure out what exactly constitutes "cute" singing and to explain that those techniques cause people to be out of tune. Of course, the word "cute" would never be used.
Hard to do though, with someone who shows up at the last possible moment. Meanwhile, I stick to my policy of not singing any words that begin with L.
It has occurred to me that most people don't get the chance to hear good choral music anymore. All they hear is soloists, whether they are opera singers or pop singers, and they assume that a good singer sounds like one of them. They don't understand that choral singers need to sing in a different way.