Cannibis smell in house while kids were in

My partner smokes cannibis but only out the back but social workers called out last night as I was about to give kids a bath and they said there's a strong smell of cannibis now they're worried about drug use in the house. My last social worker knew that my partner smokes cannibis and she said as long as its up high where kids can't reach it and it's not being smoked in house. I'm about to give birth to a baby in a few days and I'm so stressed out now