CONSTANT vigilance is a must for mothers, making sure little fingers don't end up in power points and markers stay a safe distance away from white walls.

Eagle eyes don't come sharper than Brooke Dwan's.

The Warwick mum has monitored the nutritional value of each bite of food her two daughters have eaten since they were newborns, when they were diagnosed with a rare genetic condition.

Phenylketonuria (PKU) is a life-long condition that affects one in 10,000 newborn babies and prevents the breaking down of protein.

If not managed, it slows development and causes irreversible brain damage.

Catering for 4-year-old Willow and 2-year-old Kennedy has been an ongoing juggling act for Mrs Dwan, as she must keep their protein intake below the equivalent of one egg to keep them healthy.

"That's been one of the challenges of being a PKU mum, learning all about it and all the foods they can and can't have,” she said.

"I have a diary where I write down everything the girls eat so I can keep track of every bit of protein they eat.

"If we go out for dinner and I want to give her something like hot chips, I have to weigh it and allocate it in.

"If we go out and about I always have to take snacks.

"I never leave the house without food for the girls.”

On top of preparing all the girls' meals using special low-protein alternatives, Mrs Dwan also prepares a supplement formula for them to drink three times a day.

Raising children with PKU has added another dimension to motherhood, which Brooke always knew would be challenging as she was born with a disability.

"I just adapted to life with one arm but being a mum with a disability is another challenge,” she said.

"Like being able to hold my baby and make a bottle, I can't do that. I couldn't bath them.

"My biggest support has been my husband (Matt), having him to help me.

"It's probably a bit easier now the girls are a bit older, but I just had to take my time and find my groove.”

Understanding what it's like to live life a little differently has forged a special connection between Mrs Dwan and her daughters.

"They're going to be different and I've always grown up different, so I can relate to them,” she said.

"I can give them the skills to deal with being different and teach her what it's like to accept it, because you can't change it.”

May is a special month for Mrs Dwan as alongside hosting Mother's Day, it's also PKU awareness month.

She plans to spend tomorrow catching up with family and watching her girls play happily with their cousins.