The Hamato Lily

Stealth

Each of the siblings had something they excelled in. Raph was strong and grew taller every day. Donnie's brain was marvelous and the things he made were incredible. Leo was creative with his words and charm. Lily's love of acrobatics made her very flexible. Mikey was imaginative and tried to do acrobatics like Lily, but ended up excelling with the flips and jumps instead.
"Donnie," Lily called as she walked into said brother's room, "Dad says we have training today."
Donnie was absorbed in something he was working on and explained, "Not now Lily, I'm working on some heaters for your pool."
"Why?" Lily asked, cocking her head.
"It's starting to cool down outside."
"Oh," Lily said, "Dad said if you came, you could join him and Raph on the next scavenging thing."
That got Donnie's attention, setting down what he was working on, he followed Lily to the main room.
"Good, you're all here," Dad said as Donnie and Lily lined up beside their brothers, "You have made steady progress on weaponry, but the way if the ninja is not just of weapons, it is of agility, focus, and most importantly, stealth."
There was a few moments before Leo raised his hand and asked, "What's stealth?"
"The art of moving swiftly, while remaining unseen."
"Are we gonna paint?" Mikey asked hopefully.
"No Orange."
"Like this?" Lily asked from behind Dad, startling her brothers.
Dad said, "You're silent but slow."
"This sounds like it'll be boooring," Leo said.
"Can we make it a game?" Raph asked.
Dad paused in thought for a few minutes before grabbing a few things and saying, "Hide and seek might work."
"How would it work?" Donnie asked.
"You all have to reach the bowl without me noticing your presence," Dad answered, "But, you have to do it in ten minutes or less. Go somewhere in the lair and wait until you hear the timer start."
Dad covered his eyes and ears while the siblings ran to separate corners of the lair. Then the timer started, a ticking sound telling them to begin. Raph was caught first, as his big size made it difficult to move with silence, especially since his tail has grown longer over the past month. Leo and Mikey were found at the same time, both were fast, but also loud, and the fact that they knocked over a box of marbles didn't help. Donnie's mumbled plan gave him away. Lily got within a foot of the bowl, but some boxes fell, and she shrieked, alerting Dad to her position.
It took about seven more rounds before someone reached the bowl unnoticed, and that was outside the ten minutes.
"Can we be done for today?" Lily asked, looking towards her room.
"Sure," Dad said.
Leo and Lily ran into Lily's room to use her pool/bed to soak their skin and scales.
After a few weeks, they could all get to the bowl within the ten minutes, and the triplets super-glued Dad's armchair to the ceiling, somehow. No one could figure out how they did it, not even the triplets themselves.