Meanwhile, Selena's stepfather Brian Teefey, who was also Christina's manager, earlier spoke about his heartbreak on hearing the tragic news.
In a statement, he told People: "Words cannot begin to describe the pain I am feeling.
"I learned this business through the eyes of a father and Christina was like a second daughter to me."
Christina's killer has been named as Kevin James Loibl, 27, from St. Petersburg, Florida, who police believe travelled to the concert with the intention of killing the singer.
Christina - who is known for her appearances on the US version of The Voice - opened for the band Before You Exit at The Plaza Live in Orlando.
She stayed on afterwards to sign autographs for fans when the attacker - who was carrying two handguns, two loaded magazines, and a hunting knife - approached her and opened fire.
Read more:
• Selena Gomez's family mourn Grimmie's death
• Gunman who killed The Voice star shot himself
Orlando Police Chief John Mina said it was likely the man was a deranged fan and that Christina did not know him.
He explained: "That would be speculation, but that's what it's looking like.
"There's no indication that he knew her, we're looking into that to try and find a motive for the crime."
- Bang! Showbiz
