What clothes are appropriate

I’m 19 and started nannying about 3 months ago and in Australia we’re entering spring/summer the hotter months. I’m nannying for a family with 3 girls and the parents are in their mid 30s early 40s. The mum usually lounges in cropped shirts and shorts but would it be appropriate for me to be wearing tank tops or any cropped shirts or a bikini if I’m swimming in their pool? I’m ok with not wearing shorts I usually wear pants during summer anyways.