Ah wow, what a win and what a fun package to unpack! Many congrats on so many beautiful ponies, especially the TAF babies and Cha Cha!
Your baby sea pony is Misty, by the way. They are hard to identify because hair and body can change colour and they sometimes stick between colours but the one thing that is constant with them is finpaint. Misty's fin paint is lavender, which yours looks to be xD. I think Misty is the hardest of the set to find - she certainly used to be!