Rhya went to the hospital and was diagnosed with the tumour a fortnight ago after taking ill.
She is currently in the High Dependency United of the Royal Victoria Infirmary in Newcastle.
In a show of support for the 14-year-old, famous names in sport have already thrown their weight behind a new campaign that involves making a heart shape with their hands, replicating Real Madrid star Gareth Bale’s trademark celebration.
Newcastle United legend Alan Shearer was one of the first stars to show his support.
AC Milan, the Italian giants are also planning to make hearts with their hands in their next team photograph in support of the #Heart4Rhya campaign.
Rhya is a huge football fan and supports Manchester United. She also plays for Haltwhistle under-15s girls in Northumberland and has never missed a match or training session.
She’s said that she’s missed her team mates since going into hospital, and in response, her team were the first people to get the campaign going, sending photos on Facebook and Twitter using the hashtag heart4rhya.
Rhya’s story has captivated the world and a Facebook page supporting her already has over 9,000 likes.
Kirsty Hutton owns the cafe where Rhya’s mother works and set up the group. She told the Newcastle Chronicle: “Rhya plays for Haltwhistle and, obviously, she wasn’t playing at the weekend, so they did a team photo with the girls making heart shapes with their hands.
“My dad runs another under 15s team and we come from a footballing family, so I spread the word around to try and get more teams to do the same.
“I got a few responses, so I messaged Catherine and said I had a few photos, which I sent across to her to hopefully show Rhya and put a smile on her face.
“Then, I started getting more and more messages of pictures and I thought, this is getting quite big. I spoke to Catherine again and asked if she would mind if I set-up a Facebook page.
“I made it clear I wasn’t raising money or anything like that, I just wanted pictures. Catherine said ‘That would be wonderful’ and she was really touched, so, I set the page up on Monday night.
“We don’t want any money, it is purely for people to show they are behind her.
“Now it has gone viral. The football family is massive, everybody is getting behind her.
“Rhya is putting up a massive fight.”