Develop a barbie dreamhouse party design concept for a 3-8 year old mermaid themed birthday party blank invitation inspired by the 'glittery glam barbie birthday bash.' the theme should continue to revolve around pretty black barbie doll, pink glittery background, elements, and varying shades of pink glitter and purple glitter dripping. blank space for the invitation details. this time, focus on incorporating the idea of a balloons, where black girl barbie is surrounded by sparkling stars. the invitation should exude an air of elegance, charm, and whimsy. please ensure the design remains cute, unique, fun, and functional, with an emphasis on creating a visually stunning and unforgettable invitation.