I thought they were triplets. Lotus, Aloe, and Vera.

Vera's seen just the once getting her hair wrecked by the CMC, so it's mere speculation. She shares their cutie mark, though.

1355097
From what I've read, Vera is supposed to be their cousin. I have no concrete proof that it's canon though. Just my findings throughout the fandom on various image boards, tumblr pages and such.

1358079 I suppose that makes sense. I wish we could see more of her though.

1358142 Well, it seems this group only focuses on Lotus and Aloe Blossom, and I think that Vera is only their cousin by chance.