Top shop and Dorothy Perkins, has nice dresses. I find their cutting 9n the bigger side. Not sure if its due to me being petited in size. You may also want to see carousell. There is also a plus size clothings singapore page on facebook. Try that:)
Bove, Zalora, Love Bonito. I usually also look at some blogshops tat sells baggy tops or baggy dresses, still can wear them after baby is born, example, The Stage Walk, Hollyhoque.
Jump Eat Cry https://www.jumpeatcry.com/collections/new-arrivals You can search for them in facebook too!
thanks