Alice (left) and Annie with their pet miniature horses and autism assistance dog Lizzie.
The mother of two girls with autism credits animals and a special diet with helping her daughters live full and balanced lives.
Sitting in the Walkers' kitchen with Annie, 11, as her older sister Alice, 12, chats away to a friend, it's impossible to tell the girls suffer from autism and Kryptopyrrles.
Kryptopyrrles is the production of too much kryptopyrrole in the blood and causes behaviour abnormalities such as mood swings, depression, noise and tactile sensitivities, poor tolerance for physical and emotional stress, severe inner tension, anxiety, fearfulness, and sometimes episodic anger.
The girls' mother, Sam, says the fact that the girls are thriving academically and socially is down to their contact with horses, a menagerie of animals at the family's Horsham Downs property, and a carefully monitored diet.
When the family lived in England, Sam saw a nutritionist for diagnoses.
"She did blood tests on them and both of them came back they they'd need to be gluten and dairy free, and soy free for Annie. Annie had so many allergies - spices, herbs, all sorts of things. For different reasons, [the family] are all [gluten and dairy free] so it does make it a bit easier."
The family does not 'cheat' on the diet and the result of a 'contaminated' breakfast is evident in the house - one of the girls left the bath running and the house flooded after eating gluten at a cafe which had listed the breakfast as gluten-free.
"The gluten causes brain fog, it acts like a morphine. The morphine particles pass into the brain and affect their behaviour and their thinking. They can't unscramble all the words [when someone is talking to them]."
People with allergies to milk and wheat often have issues with the peptides (a compound of two or more amino acids linked like a chain) in gluten, which react with the brain and mimic effects of opiate drugs like heroin and morphine.
Sam said by cutting out gluten and dairy it takes away the brain fog and helps the girls to think clearly.
"Their behaviours are better because a lot of autistic children tantrum all the time and these two are beautifully behaved.
"We did go to a cafe and had the gluten-free breakfast. Before they'd even finished eating I thought there is gluten in that. Oh my gosh the behaviour... up and down, running in and out of the toilet.
"If we stick to a diet of gluten-free, dairy-free, and lots of organic food, and no nasties, their behaviour is better, their learning is better."
Along with the diet, Alice attended Riding for the Disabled (RDA) when they lived in the UK. Struggling with autism, RDA was a way to get her to speak.
Sam says animals have been one of the main things to help both the children become balanced.
"They've gone from not talking, and not being able to do very much, to thriving academically, with sports, with music, a ridiculous passion for horses," Sam said.
Though Alice enjoys horses, it is Annie who is bent on having her own pony. For now, there are two miniatures in the large backyard and she is riding a pony called Jaggar at the Waikato Equestrian Centre, winning show jumping classes with him. Annie has managed to save up nearly $2000 of her pocket money to go towards a horse one day.
When the family moved to New Zealand, the girls stopped RDA but have attended regular riding lessons.
"Alice was the first one we noticed a difference [when we started RDA], she started a year before Annie. Alice didn't speak, same with Annie. When Alice went horse riding, she'd speak after she'd ridden and then she would speak all the way home for the hour. As the week went on, she would speak less and less, then put her back on the horse.
"If we are ever having a bad time or the autism is rearing up, I book an extra lesson and send them in. Even if it is just walking around the paddock rather than a lesson."
The family has almost 30 animals at their lifestyle property, including a mouse, fish, miniature horses, dogs, and chickens. One of the dogs, Lizzie, came to the family as an assistance dog, and was trained to soothe an autistic tantrum by lying over the child or nudging with her nose until she was patted and cuddled.
Now she is a companion dog as the girls are doing well, but Sam says if Alice is having a bad day she sends her to her room and tells her to take Lizzie.
"They just cuddle. It doesn't matter what you say to the dog, they just want the cuddles.
"An autistic child often doesn't want to be held by a human, that is where the interaction with dogs and horses come in."
Sam will often talk to autism groups about the impact the animals and diet have had on her daughters.
"It does just make such a huge difference to them."