"She might have a day which is seizure free, nice and calm, or she might start the day with a huge seizure which will cause her to be tired throughout the day and unsettled."
Seizures are one of the many problems caused by the tumour, with medication to treat them often coming with unpleasant side effects as well.
"Ideally, we would love to have Renee completely free of seizures, as that would make a huge difference to her life."
In the hope of achieving that dream, Alison, husband Leon, Renee and Hollie are about to fly to Houston, Texas in the United States, where Renee will undergo stereotactic laser ablation brain surgery.
This isn't the first brain surgery Renee has had. In 2013 she underwent open brain surgery at Starship Hospital in an attempt to remove the tumour.
Some of was indeed successfully removed, but part of it, and many of the related problems, remained.
"We have never given up hope, so while it seemed we had reached the end of options here in New Zealand, we kept on looking and doing our own research," says Alison.
She and Leon spent hours trawling through websites about the condition, looking for their own rainbow.
They finally found it in the work of Dr Daniel Curry and his team at Texas Children's Hospital.
"He really is a pioneer in developing a way to treat the tumour in a minimally invasive way.
This is keyhole surgery not open and the results they have had from this technique are incredibly positive."
The Eagars talked about Dr Curry's work with Renee's neurologist at Starship, who agreed it seemed like a viable option.
Renee's details were sent to the team in Texas, who agreed she was a good candidate for the surgery.
"We then applied to the Ministry of Health to fund the surgery, and we are so fortunate they have agreed to do so."
The Ministry will fund the costs for Renee and Alison to travel to the USA for the surgery, and the costs of the surgery there.
"Which is fantastic, and we could not have considered this surgery without that funding."
Now, the challenge for the family is to raise enough money for Leon and Hollie to go with them.
"It would be incredibly hard for me to go on my own," says Alison, explaining she and Leon "tag team" caring for Renee.
"And Hollie does a lot too. We have all spent the past 11 years learning how best to help Renee and how to respond when she is upset or anxious."
A givealittle page has been set up by Renee's uncle, to raise money to help cover the numerous costs associated with the family travelling to the States and then the expenses which will occur while there.
"The last surgery Renee had, she was expected to be in for two weeks. That ended up being a two-month stay in Auckland."
Alison says it is impossible to predict how well the surgery will go, or if a complication such as last time, when Renee didn't wake up for three days after the surgery, will occur and increase their costs.
"We just have to go with it, and see what happens. But whatever does happen will be far easier to deal with if we are there together."
Local charitable group, Team HOPE has been hard at work supporting the family.
Renee was the first child they helped, back in 2014. At that time the group of caring locals wanted to do "something nice" for Rene, after her brain surgery, since then they have helped numerous individuals in the area.
"They have been a constant support," says Alison, "and we are really grateful for all they have done".
She says the givealittle page has been "humbling" to watch grow since it started last week.
"The fact so many people, strangers to us, have given to help us find that pot of gold for Renee is just so amazing. We can't say thank you enough."
Renee isn't a fan of hospital stays, but is looking forward to going on the big plane. So is her twin Hollie, although Hollie's favourite part of the trip is going to be "flying home with Renee being all better".
- www.givealittle.co.nz/cause/renee2america
