The longer story
It depends entirely on how it is used. Asking a chatbot to explain a concept a different way, to quiz your child before a test, or to check whether an answer makes sense can genuinely support learning. Asking it to write the essay does not, because the struggle is usually the point of the task. A rule that works for many families is that AI may help your child understand the work, but the words they hand in should be their own. It is worth checking your school's policy as well, since most now set out what is and is not allowed, and the expectations often differ between subjects and year groups.