Mia, from Pembrokeshire, has been selected to compete as Little Miss Wales in the Pure International finals in Orlando, Florida at the end of June.
Her mother Chloe said she has received criticism and even abuse from people for allowing her daughter to become involved in pageants.
She said Mia got a lot of confidence from competing.
“She learns a lot of public speaking, she takes a lot of criticism as well as positivity,” Chloe told BBC Radio Wales’ Good Morning Wales programme.
“She learns to be the best person she can be. She learns how to interact with people, how to get up on stage and speak in front of hundreds of people.”
Chloe said she began to look into pageants when Mia was four, after speaking to a friend whose daughter took part in them.
“After doing a lot of research into it and making sure it was the right pageant, I sat down and spoke to Mia, and this was something she really wanted to do.”
Mia went on to win Little Miss Cardiff 2017 and Little Miss Sunshine, and after coming second in the Pure UK national finals she will compete in the United States.
Chloe said she understood criticism of her decision – with people concerned about body image – but said beauty pageants were often misrepresented.
“I think the media portrays beauty pageants to be bad, showing them on television all glitzed and glammed up with hair extensions, fake tan and make up, making them out to be spoilt and selfish children, which really isn’t the case.
“I understand everyone has their own opinions… and I accept the criticism, but I do not accept abuse.
“It does frustrate me a little bit but I do understand also that people aren’t 100% aware of what actually goes into beauty pageants and what it entails.
“It doesn’t matter what you look like on the outside, it’s who you are on the inside, what type of person you are. It doesn’t matter if you’re big or small, tall or short.”
Chloe added while she was hoping Mia would win in Florida, they were just happy to compete.
“Everyone who enters are winners anyway, without the crown or not.”