If I transform this sentence, She said," Don’t the children like the ice-cream? " into the reported speech sentence as follows : She was heard saying that the children didn’t like the ice-cream., is it grammatically correct?
I would say:
“She said that the children didn’t like the ice-cream.”
The speaker is asking a question and so that has to be indicated in the reported speech -
She wondered whether the children (really) liked the ice cream.