I’m thinking of doing a little ‘siblings/headcanon families’ thing, so have my headcanon; Birch Bucket and Lavender Essence are the parents of Vera Veil, Aloe Allure and Lotus Blossom… Well, the parents of Vera Veil. See, while you likely won’t remember because it isn’t something I revealed myself, but was going to be revealed in the Ask Quasimodo Quartz tumblr that Aloe and Lotus are not in fact ponies (click for their appearances as changelings), but the last two Spa Drones; they based themselves off of Vera who found them alone and scared and brought them home with her. They’re very old, in that way… but they consider Lavender and Birch their parents anyway, having a second childhood with their sister Vera… they still work as Spa ponies, and after all, spas are made to hide your age…  
Don’t expect all of these to be super secret headcanons, a significant number are just gonna be headcanon messes. And anyway, this is already a spilled secret, just something not all of you know.