Does "Vem liknar barnet?" not mean "Who looks like the child?" rather than "Who does the child resemble?", and if not, where does the difference lie.
It can mean both actually. The difference lies in context and intonation.
This would seem like a huge issue, especially with other verbs.
As I said, context and intonation takes care of that, so it’s not a huge issue.
How would you say "who resembles the child?"
see above. the same way. potential ambiguity, resolved by context