DH's friend and his partner are staying for a few nights. I've met her on 2 occasions, she seems very nice, normal, friendly.
On their arrival I told them to help themselves to anything from kitchen, showed them the snacks cupboard, fruit, fridge etc. Plenty of biscuits, chocolate, crackers, cake, yogurts, cheese etc. Baby food is in bottom half of cupboard.
This morning I found 2 empty jars of Heinz baby porridge in the recycling, along with an empty pouch of purred mango. Mid-morning I noticed her eating a baby cocoa-vanilla dessert straight from the jar! 
I don't know what to do! DH thinks it's hilarious and says not to mention it. I'm irritated as the jars are expensive, they are for DS and there is plenty of other food.
AIBU to think this is really weird and rude? Should I hide the jars or let her carry on?