Our neighbours have gone away for a couple of months over the summer to visit family abroad. While they are away, the sister of one of them is housesitting. Pretty much everyday since she has been at the house, she has sat in the garden smoking weed. This starts at about noon and carries on into the evening. The smell in our garden is so strong and I particularly dislike the fact that it stinks out there when our baby and toddler play in the garden. We are on friendly terms with the neighbours, but don’t know the sister at all. How would you deal with this?