What can I say? That wall eyed background pone is my favorite and I REALLY love the small (well, not really small XD) family the fans gave her. So, I decided to headcanon her lineage and as you can tell from the title, all of them are fathered by Doctor Whooves. Below, I put my fanon descriptions of them so they may or may not directly correlate with how most of the fandom depicts them (and also, some of my own headcanons for Doc and Derpy).
Amethyst Star Sparkler
The oldest among the siblings, she was conceived and born during one of the Whooves couple's time travel adventures. As a result, she aged up quite fast and by the time her parents returned to Ponyville, she was already a teenager. Like DJ, she's closer to her father and it may be because she's somewhat annoyed by her mother's antics (don't worry, she still loves her, derped eyes and all). Since their family is quite huge, she helps earn some money by working as a babysitter and is often called by Lyra and Bonbon to look after their little Toots. Earned her cutie mark during one of her parents' adventures.
DJ Whooves
The pleasant surprise of a result of one of Doc's experiments. He was made when Derpy's eccentric Doc tried combining his DNA with hers, creating a colt who had all his father's looks but his mother's energetic and upbeat character. Doc often brings him on his time traveling adventures, so it's quite common for him to be away with his father. Earned his cute mark when he helped his father on a time travel adventure.
Crackle Pop
The first Whooves child who was born without any science-y thing affecting it. Crackle is closer to his mother but often is looked after by her relatives in Rainbow Falls, which is why he's often not in Ponyville. Due to his love for competing in the annual race and being a mama's colt, he's nicknamed "Derby Hooves". He's unaware that his rather good nature attracted Lyra's little filly, Tootsie Flute, to him. It's unknown how he earned his cutie mark.
Dinky
A big mama's filly and another one of Derpy's children who inherited her grandfather's unicorn genes. She's best friends with Tootsie Flute and wants to learn how to conjure the perfect muffin. She's also closer to Amethyst mainly because they're often the only Whooves siblings in Ponyville and likes to join her mother in her antics. Loves doting on Dipsy.
Chirpy
Along with Crackle Pop, she's usually looked after by relatives in Rainbow Falls. She has quite the eye for collecting and usually, her visits to her parents' current home is for finding more things to add to her collection. She wishes to one day, compete in the derby race with either one of her older brothers.
Dizzy
Another pleasant result of the Doctor's experiments only, she has more of Derpy's genes in her. She inherited her father's ability to quickly be in another place and time but usually uses it for fun and to not be late for school.
Dipsy
The last muffin in the basket and another foal who inherited Derpy's father's unicorn genes. Like Crackle and Chirpy, he's often in Rainbow Falls, being looked after by relatives. Although he's still a baby, he seems to have a potential to be a great artist, which my be due to usually being looked after by his uncle Ponet.