8 little-known facts about Bellatrix Lestrange even die-hard 'Harry Potter' fans may have missed

• The villainous Bellatrix Lestrange was one of the most feared characters in "Harry Potter."
• She was married to another Death Eater for many years, and her sister was disowned by her family.

Lord Voldemort may have been the ultimate villain of the "Harry Potter" series, but Bellatrix Lestrange was evil, sadistic, and worst of all, always striving for the Dark Lord's love and respect.

Before using her platform to spread transphobic messages, the series' controversial author, JK Rowling, used Twitter, interviews, and the official Wizarding World website to expand the "Harry Potter" canon beyond the seven books.

With all this information and the original series in mind, read on for some facts about Bellatrix that even the biggest "Harry Potter" fans might not know.

Bellatrix Lestrange was married to a fellow Death Eater

Bellatrix was born into the Black family, so it may be obvious to some fans that she got married at some point, given her surname.

But not much information is given about her husband, Rodolphus Lestrange, in the book — and he's not a character in the movies — so it's easy to forget the witch was ever married.

As Death Eaters, Rodolphus and Bellatrix participated in some of the most hideous crimes in the First Wizarding War, including the torture of Alice and Frank Longbottom.

Helen McCrory was originally supposed to play Bellatrix in the films

The late Helen McCrory was set to play Bellatrix in "Harry Potter and the Order of the Phoenix." But she became pregnant prior to filming and was unable to play the role.

Helena Bonham Carter was then cast, and McCrory was ultimately brought back in "Harry Potter and the Half-Blood Prince" to play Bellatrix's sister, Narcissa Malfoy (née Black).

Several members of the Black family are named after stars

Rowling has been known to choose character names with deeper significance. In the case of the Black family, she pulled from astronomy.

Orion is a very famous constellation and also the name of Sirius Black's father. Sirius is named after the brightest star in the sky, sometimes called "Orion's Dog." Regulus Black, Sirius' brother, is named after a star in the Leo constellation. And Bellatrix is the name of a star in the Orion constellation.

Bellatrix also translates to "female warrior," which is fitting because the "Harry Potter" character is one of the few Death Eaters who's a woman.

Bonham Carter made her own mark on the character

In a 2010 interview with Entertainment Weekly, Bonham Carter revealed that she came up with some of Bellatrix's most memorable characteristics.

She said, "there wasn't a huge amount on the page originally," so she decided to play the character even more "unhinged" than planned. She also suggested Bellatrix's rotten teeth to further the "savage" imagery and represent the years she was locked away in Azkaban.

But she still wanted the character to be sexy by wearing tight corsets.

The costume department had to make some adjustments to her wardrobe designs in "Half-Blood Prince" because Bonham Carter was pregnant. Her clothing is noticeably looser in the sixth film.

Narcissa Malfoy wasn't Bellatrix's only sister

As a cousin to Sirius and Regulus Black, we know a lot about Bellatrix's extended relatives, but not as much about the ones closest to her.

In the "Harry Potter'' films, Narcissa Malfoy is the only one of Bellatrix's siblings who's introduced. But Bellatrix is also the older sister of Andromeda Tonks (née Black).

Andromeda, mother to Nymphadora, was disowned by the Black family for marrying a Muggle-born wizard, Ted Tonks.

Rowling said she always knew Molly Weasley would kill Bellatrix

Some fans thought that Bellatrix's demise would come at the hands of Neville Longbottom, as a way to avenge his parents after Bellatrix and her husband tortured them.

But ultimately, it was Molly Weasley who killed Bellatrix while defending her daughter, Ginny, during the Battle of Hogwarts.

During a 2007 event at Carnegie Hall, transcribed on The Leaky Cauldron, Rowling said she always knew Molly would defeat the dark witch because she wanted to display Molly's sometimes-underappreciated power and highlight the force of maternal love.

She had a child with Voldemort

In the play "Harry Potter and the Cursed Child," which has become part of "Harry Potter" canon, it was revealed that Bellatrix conceived a child with none other than Lord Voldemort.

Their daughter, Delphini, was born sometime between the Battle of the Department of Mysteries and the Battle of Hogwarts, which ended with the death of both of her parents.

Bellatrix always appears on Voldemort's right side in the final film

The filmmakers of "Harry Potter and the Deathly Hallows – Part 2" decided to take the phrase "right-hand man" quite literally when it came to Bellatrix and Voldemort.

Bellatrix always appears on Voldemort's right side because she was one of the few remaining unwavering Death Eaters by the final film.