I do think the rules are different when they're, say, under 10: first because they're incredibly unlikely to have the capacity to do any material harm, and second because they are reasonably likely to actually not know why they shouldn't do that and be capable of learning otherwise.

That doesn't mean you're obligated to follow the advice if you'd rather not engage but a seven-year-old stalker has a reasonable chance of turning into an actual friend if you want one. A forty-year-old one doesn't.