Lainie Williams, 17, was found with fatal stab wounds at the address in South Wales, with her mother found seriously injured.
Cameron Cheng, 18, was arrested after police were called to reports of a stabbing at the family home in Wheatley Place, Cefn Fforest, South Wales, at around 7pm on Thursday.
Armed police were involved in his arrest, which took place five miles from the family home.
Police arrived at the address to find Lainie Williams with fatal stab wounds, with her mother, Rhian Stephens, 38, seriously injured.
Cheng, a British national from Newbridge who is believed to be known to Lainie, was also charged with possession of a bladed article.
He is to appear at Newport Magistrates’ Court on Monday.
It comes as Lainie's family praised the 'brave' 17-year-old schoolgirl. having spoken of their heartbreak in the wake of her death.
According to Lainie's heartbroken grandfather, Robert Stephen, the 17-year-old told her eight-year-old brother, who witnessed the attack, to hide under the bed in a bid to save him.
He alleges the attacker waited for Ms Stephens' partner, Clive Osborne, to leave for work before entering the home, according to The Sun.
In a heartbreaking reflection, Lainie's cousin, Megan, wrote on social media: “There’s not enough words, rest peacefully our brave and beautiful cousin Lainie.
"Very fond childhood memories I’ll cherish forever.“You were and still are so loved.”
Neighbours have recalled hearing screams around the time of the attack, with police confirming the 18-year-old suspect remains in custody following the attack.
Following the attack, Lainie's cousin, Megan, paid tribute to her saying: "There's not enough words, rest peacefully our brave and beautiful cousin Lainie. Very fond childhood memories I'll cherish forever. You were and still are so loved."
Neighbours have described Lainie's mother as a "caring person but who kept herself to herself".
Cefn Fforest Councillor Shane Williams said: "We are all deeply shocked and saddened by the events that have unfolded, and I understand that the police are not looking for anyone else in connection.
"But as councillors, we’d like to do our best to reassure everyone, and our thoughts are with the family at this time.
“We are all hoping for a full recovery for the woman who was hospitalised. Something like this is highly unusual in this area, and I can understand if many residents are now frightened.
"When a young girl loses her life like that, it’s quite horrendous."
Following the tragic news, Detective Superintendent Philip O'Connell, the senior investigating officer, said: “We can confirm that we’re not looking for anyone else in connection with this incident after making this arrest earlier.
"We understand that reports of this nature can be concerning, and it is likely that residents will see an increased number of officers in the area while we carry out further enquires.
"If anyone has any information, please speak to our officers or contact us in the usual way.”
Anyone with information is urged to get in touch with South Wales police by calling 101, messaging Gwent Police on social media or through the form on their website quoting reference 2500361653. You can also contact Crimestoppers anonymously, either online or by calling 0800 555 111.
