Ally is larger than an average little girl due to the experiments done on her during her time in captivity. She wears a light colored sleeveless dress and has dark hair. When Kin'emon gave out coats, hers was light colored with dark fur on the hood and ends of the sleeves. It also had dark buttons.
She is a normal timid little girl, as she was scared by Kin'emon's severed head.
Punk Hazard Arc
At some point, Ally was taken from her parents after being told she was sick and would be made healthy again. She stayed with the other children in Biscuits Room on Punk Hazard until the Straw Hats broke them out. Later, she succumbed to the withdrawal symptoms of NHC10, which she and the other children were fed regularly in candy form. Usopp eventually knocked out the children with sleeping gas, and the Straw Hats chained them all up for safety reasons.
Later, when the Straw Hats had infiltrated Caesar's lab, Mocha and Chopper kept the wild kids from going to the Biscuits Room. When Ally and the kids finally advanced, they chased Mocha, who had taken all the candy, and attacked Chopper in his Monster Point. They soon reached the Biscuits Room and overrun Robin's Mil Fleur technique in their run. Mocha ran on and the kids follow soon after, while being chased by Robin, Nami, and Chopper. They eventually cornered Mocha and attacked her, trying to take the candy from her hands. However, Mocha ate the whole batch and Ally, among others, got mad and attacked her. Soon after, the Marines arrived and subdued Ally and the other kids, for Chopper to sedate them. Ally was quickly put to sleep.
After she woke up from her sleep, she ran with Nami, Robin, Sanji, the G-5 Marines and the other children to the exit of the Building R. Soon after Law cut the entire laboratory, the gas, Shinokuni started to seep in which scared her along with the other kids. At the same time, the group joined up with Zoro and Tashigi who came running towards them and continued to run to the exit.
The group eventually reached the exit and joined up with Luffy and his group. Soon after that, Law and Smoker reached the exit with a cart that Law meant to use for escaping the laboratory. When the rest of the children, Straw Hat pirates, Caesar’s subordinates and G-5 Marines reached the exit, the survivors started escaping from the crumbling laboratory.
While everyone was escaping through the tunnel, they heard an explosion coming from Building D. The explosion caused the corridor to collapse. Law noted that if the tunnel was part of the mountain that if it collapsed they would be buried alive. Despite this, they eventually reached the exit safely due to the actions of Zoro and Luffy. Upon breaking through the exit and reaching the outside world, Ally noticed the Franky Shogun along with the other kids and the G-5 Marines.
After Caesar Clown, Buffalo, and Baby 5 were captured, Ally was seen along with the other kids after having the medicine in their bodies removed by Law. They stated their concern about Mocha's well being, but Chopper assured them of her safety by saying she will wake up soon. Then, they asked where Nami is and ask if she will take her home. Tashigi entered the room however, stating that the Marines would take care of them now, much to their disliking. Soon after, Ally and the others were seen gathering around the food Sanji made with bowls in their hand and drooling mouths. Not long after that, all the survivors started a party together.
When the party came to an end, Ally and the other kids were escorted by the G-5 Marines on to the tanker. While the Straw Hat pirates were preparing to leave as well, Nami said to Chopper that Vegapunk was going to help cure the kids from the effects of the candy. As they began to leave, the Marines put up Marine banners to prevent Ally and the others from seeing the Straw Hat pirates while saying that the marines are justice and pirates are scum. Ally and the other kids still wanted to see the Straw Hat pirates and told the Marines to move. The Marines responded to them by pointing their rifles at them saying that only bad kids want to see pirates.
However the kids insisted that the Straw Hat pirates tried to save them even though they knew nothing about them. However, the Marines kept insisting that pirates are always evil and that they are justice. Tashigi then interrupted them and said they were a disgrace. The G-5 Marines told her that if they did not bad mouth the pirates, they would come to respect them. Finally the Marines gave in and let Ally and the other kids say their goodbyes. They also stated that they would become pirates too when they grow up, regardless of the disapproval the G-5 Marines gave them.
While traveling with the G-5 Marines, Tashigi informed the children that they would see Dr. Vegapunk in a few days.