However, behind the smile 18-month-old Rosannah, who was born in Baradine, is dealing with a tumour that reaches from her lower abdomen all the way to her heart.

In early December she was diagnosed with stage 3 neuroblastoma and has since undergone four rounds of chemotherapy, but unfortunately Rosannah's family has just been hit with more hard news.

"The chemotherapy has failed epically. It didn't shrink the tumour to even a quarter of its size," Ms Searle said.

"When we found out that it didn't shrink as much as expected the doctor said she could look into having a stronger more intense chemo or have surgery to remove part of it but we found out chemo is out of the question completely."

Ms Searle said the doctor has consulted with other specialists world-wide and a highly regarded neuroblastoma surgeon in New York has strongly recommended against surgery.

"We're just waiting to see what the other surgeons say. We'll probably hear back this week or next week."

The family are adamant that regardless of the news, they'll continue to fight for Rosannah.

"I'm not giving up. I'm going to keep doing everything I can," Ms Searle said.

"Amy [Searle] and I are trying to fundraise for Rosannah to make sure she gets the treatment."

She said it was going to take a lot to knock Rosannah down.

"On her good days you wouldn't even be able to tell she was sick except for her being pale and having a big tummy. She's just like any other toddler."

In February, Rosannah welcomed a new sister into the family.

"Little Skylar came in on February 19, two days before Rosannah's last round of chemo. The day she was born Rosannah was all over her," Ms Searle said.

Currently, Ms Searle said she was taking care of Skylar in Coonamble so Rosannah's parents can stay with her in Sydney. More information about Rosannah can be found at the Help our Baby Girl Rosannah Facebook page and donations can be made at www.gofundme.com/sweetbabygirl.