The 22-year-old singer, who formerly appeared on U.S. television talent show The Voice in 2014, was killed last week when 27-year-old gunman Kevin James Loibl opened fire during a fan meet and greet after her concert in Orlando, Florida.

Her family, including brother Marcus who tackled Loibl after he shot Christina, will pay their final respects to Christina with a viewing at the Fellowship Alliance Chapel in Medford, before a memorial service will be held there on Friday night.

"It's just going to be a small, intimate gathering for her family and close friends," a source told People.

Further details of the service have been kept private. However, Marcus previously revealed that Maroon 5 frontman Adam Levine, who mentored Christina on The Voice, had generously offered to pay for the funeral.

In the wake of the shocking death of Christina, several stars have come forward to reveal their doubts about whether or not similar fan meet and greets should still take place.

Nick Jonas spoke to KTU radio station's Cubby & Carolina Bermudez on Tuesday (14Jun16) and said security needs to be stepped up.

"I was talking to my manager about it the other day," he said. "Interestingly enough, in an interview a while ago, he mentioned that he thinks that security needs to be increased at venues. Just something that should be looked at. I think it's obviously very poignant."

Nick also tackled the issue during an interview with Elvis Duran and The Morning Show on Monday (13Jun16). Orlando has been in the headlines over the past week not only due to Christina's shooting but also due to the mass shooting at Pulse nightclub in the city last weekend, where 49 people were killed and 53 more injured.

"It's something that needs to be addressed across the board and it's not just specifically in meet and greets, because obviously the horrible tragedy in Orlando the next day..." Nick said. "I think it's just an issue we need to sort out as a country and get right. With music venues, I think there are some protocols that can be taken to make it safer, not only for the artists but for the fans. We all need live music, we need to be able to feel safe to go to a show and enjoy a concert. We can't let people win that are out there just to make people’s lives horrible."