A small explanation of how this will work, because I will be experimenting with AU's along the line I will write the information at the beginning of each story. Such as how old the characters are at the are at the time, I wont bother with the ages of the adults unless it's really important. If there is an AU I will put it at the beginning, if not, just the ages.

Natty - 10

Natty was excited; it was her birthday next week which meant she was going to get gifts and cake! She loved her birthday, at least she always had since she started living with Sherlock, before they were nothing to look forward to, the streets don't care if it's your birthday or not.

Last year John had given her a book all about the unsolved crimes on England. Her father had actually been jealous, so John ended up buying one for him as well. Natty laughed at the memory.

"Natty are you even paying attention?" Sherlock sighed bringing her back to reality.

Sherlock had been teaching her about the different kinds of fingerprints and how to recognise them without a computer.

"Sorry Dad." She muttered.

"Your birthday is still six days away, why get so hyped up now. It's interfering with your work." Sherlock chastised.

"Sherlock, kids get excited about their birthdays." John laughed from the living room where he was updating his blog, "You can't stop it."

"I can try." He sighed.

Natty giggled.

"Since we are on the subject what do you want for your birthday?" Sherlock asked casually, turning back to the microscope on the table. Natty tilted her head, smiling in thought.

"Can we get a puppy?" She asked.

"You already have Gladstone." Sherlock replied, still focusing on his slide.

"Yeah, but I want a cute fluffy one." Natty replied, "Or one of those new Princess Barbie Dolls."

Sherlock stared at her with his mouth slightly agape, oh dear she must of broken him. Actually John had the same expression on his face. Natty burst into laughter.

"I'm just messing with you Daddy," She giggled before replying seriously, "I want a benchmade model 42 balisong butterfly knife."

Sherlock let out a sigh of relief.

"Natty you had me worried!" he scolded.

Natty cackled like a maniac.

…

As expected Natty's birthday was a lot of fun, Lestrade even joined the group for a game of cross London hide and seek which ended with Joe tackling their father so hard they were both seeing stars.

She got a multitude of books, games and science equipment from her brothers and sisters, John gave her some music and Lestrade gave her a fake Scotland Yard ID. That last one would come in handy one day. Finally Sherlock handed her a small black box, which was unwrapped, Natty clicked it open to find two balisong knives nestled in the foam.

"Oh thank you thank you thank you!" She squealed squeezing all the air out of his lungs. Sherlock chuckled as she ran back to the little box and flicked one of the knives out and began to twist and turn it like a nun chuck.

"Yep, that's an appropriate gift for a ten year old." Lestrade mused aloud, though he didn't really mean any offence.

"Just don't slice your fingers off Natty." John warned.

"I know what I'm doing." She sighed, "Watch this!"

"She spun the two knives around with speed and precision, she could tell her dad was impressed.

"Oh and one other thing." Sherlock continued reaching behind his chair and bringing out another box, this one was wrapped in florescent pink paper. Natty could just imagine her father buying the paper in his dark outfit, how odd he must have looked.

"Yes, I did get quite a few looks." Sherlock replied, seemingly deducing her thoughts, "Now open it."

Natty ripped the paper off with enthusiasm only to freeze when the paper finally came off. The room burst into laughter, Mason actually fell on the floor trying to breath. John was doing his best not to laugh, covering his grin with his hand but the sight of Sherlock chuckling broke his resolve and he was leaning on his knees trying to catch his breath.

"Well, you did ask for it." Sherlock grinned evilly.

Natty turned an impressive shade of red as she looked down at the object in her hand. The doll was blonde, just like her, but decked out in a huge pink ball gown, coated in jewels and sequins. She wore a shining gold tiara on her head. A bloody barbie doll.