I know people who use it for nausea purposes I never smoked that during pregnancy I've tried it beforehand but don't see the hype about. But with heroin and narcotics on the rise I would definitely watch out because they drug test immediately after birth.
I wouldn't say it helps. but there's no harm in it unless she wants her child taken away after its born. my sister in law smoked throughout both of her pregnancies and her boys are healthy and smart as can be