Bellatrix is a member of the Black Family and is the cousin of Sirius Black. Bellatrix is the daughter of Cygnus and Druella Black and sister to Andromeda (mother of Nymphadora Tonks) and Narcissa (mother of Draco Malfoy).
Draco's mother is Narcissa Black, which makes Draco Sirius' second cousin.
Yep, that happened: Bellatrix and Voldemort had sex sometime around Order of the Phoenix or Half-Blood Prince, and their wild night in bed led to a child named Delphi Diggory/Riddle/Lestrange. According to Delphi herself, she was born sometime before the Battle of Hogwarts.
Narcissa, Bellatrix and Andromeda were Sirius's cousins, so they would not have grown up in the same house as him. Sirius only had one sibling - Regulus.
His parents, Orion and Walburga Black, were both Blacks by birth and second cousins. Sirius had a younger brother, Regulus Arcturus Black, and three older cousins: Bellatrix Lestrange, Andromeda Tonks (his favourite cousin and mother of Nymphadora Tonks), and Narcissa Malfoy (mother of Draco Malfoy).
Harry, Ron and Draco are cousins.
Harry is Rose's uncle because of his marriage to Ginny who is Ron's sister. In addition to that, they are very distant relatives through the Weasley and then the Black bloodline.
– Andromeda is several years older than Sirius; Sirius was born in 1959, so there is about a six year age difference between the two. Andromeda attended Hogwarts in the mid-60s to early 70s, while Sirius attended Hogwarts from 1971 to 1978.
↑ 1.0 1.1 The Black family tapestry shows that Andromeda is younger than Bellatrix, who was born in 1951, and older than Narcissa, who was born in 1955.
Funnily enough, the most famous Lestrange is one only by marriage, and despite really adorable Instagram photos that make us wish it so, there is no blood relation between Leta and Bellatrix whatsoever. At most, Leta and Rodolphus Lestrange (Bellatrix's husband) are very distant cousins.
Delphi finally appeared and Harry (disguised as Voldemort) pretended not to know who she was. She explained that she was the child of Tom Riddle and Bellatrix Lestrange.
Delphini's birth was one of the most well-guarded secrets of Voldemort and his servants. She was sent to live with Euphemia Rowle, who only raised her because she was offered gold, though we don't know who paid her.
His Child-Form When Resurrected
Pettigrew mixed up a potion for Voldemort using unicorn blood and the venom of Nagini. With this potion, they were able to create a new body for Lord Voldemort to finally return to.
I truly believe Luna and Draco are cousins. Luna's mother has to be Lucius' sister, in my eyes. Hagrid said all Purebloods are related one way or another, and I think he's right. Movie Luna and Draco look so much alike, they just have to be family.
According to the Black Family Tree, Sirius Black and Andromeda Tonks née Black are first cousins. This means that Nymphadora Tonks (Andromeda's daughter) is Sirius's first cousin once removed.
Tonks was fully capable of making her own choices and Sirius and Andromeda supported them both. He married her because he loved her.
She was a Metamorphmagus and attended Hogwarts School of Witchcraft and Wizardry from 1984 to 1991. She was sorted into Hufflepuff House and was in the same year at Hogwarts as Gryffindor Charles Weasley.
Andromeda's status as a member of the Black family undoubtedly contributed towards her being sorted into Slytherin, but she eschewed all of the darkest beliefs of her family and seemed to be an amalgamation of all of the best traits that Slytherin house has to offer.
His favourite cousin, Andromeda, was disowned by the family as a "blood traitor" when she married Ted Tonks, a Muggle-born wizard. Sirius would later share this designation and was held in contempt, even hatred, by some members of his family.
Tonks attended Hogwarts School of Witchcraft and Wizardry from 1984 to 1991 and was Sorted into Hufflepuff House. She was in the same year at Hogwarts as Gryffindor Charlie Weasley.
Technically Harry and Draco are related bc Sirius is Harry's godfather and Sirius is bellatrixs cousin who is Dracos aunt! Harry is distantly related to Voldemort, too, as they both are descendants of the Peverell brothers. Harry's ancestor is Ignotus, and Voldemort's is Cadmus, so they're very distant cousins.
Harry is descended from both Salazar Slytherin (through his mother) and Godric Gryffindor (through his father).
Ron's family is big. Both Molly and Arthur are from old wizarding families (the Prewett's and the Weasley's) and at Bill and Fleur's wedding, Harry is 'another one of those Weasley cousins'.