Craft an enchanting hand-drawn watercolor clip art image featuring a family gift niche with birth flowers representing a family of three: a April baby (Daisy), a September baby (Aster), and a December baby (Poinsettia). Make the image customizable, allowing users to choose their own birth flowers. Add delicate details, such as subtle watercolor strokes and shading, to create a captivating and sentimental piece of art.