"Look Sherlock I get that you don't want another partner but frankly I don't care." Mycroft followed Sherlock as he paced the room.
"Look here DEAR brother, I do not want another partner, I do not need another partner, NOW GO!" Sherlock pointed towards the door and Mycroft began to slowly walk towards it.
"She'll be here tomorrow at 7, be nice Sherlock." With that Mycroft walked out the door with a smug smile on his face. John was on his honeymoon with Molly and wouldn't be back for almost a month. Until then he was alone to solve his cases. Mycroft insists that Sherlock gets a temporary partner until then. From his understanding she was a girl who was just like him, a high functioning sociopath.
Sherlock looked the the door and picked up his violin. He played the same tune for the whole night.

It was morning and the sun was high. Today was one of London's hottest days. Kids were running around in shorts eating ice cream. Sherlock looked at his phone, 6:10. His 'guest' would be arriving in 50 minutes. He took that time to shower and get dressed. At exactly 7 there was a knock at the door. It was Mycroft with a woman behind him.
"Hello baby brother, this is Aniese Harts your temporary partner until your boyfriend returns from his honeymoon." Aniese looked at Sherlock confused.
"He is not my boyfriend Mycroft, he's married to Mary. You would know if you came to the wedding." Sherlock sat on his chair and looked at the two.
"You seemed to have everything under control, I saw no need to go." Mycroft sat down across from Sherlock who didn't stop looking at Aniese.
"5'8, Scorpio, 135lbs, American but your parents are from Puerto Rico. Multiple tattoos, a new one on your arm. Full in all the right places, above average according to normal male standards. Un-natural hair color, obviously. You seem to have heterochroma (mixed eye colors) Hmmm, also a high functioning sociopath, like myself." He smiled at the fact he realized who you were.
"6'0, English, perfect skin, natural hair, above average to normal female standards, incredibly smart, younger brother, virgin, and habits I myself have." Aniese walked towards the young detective.
"And what would that be?"
"Maybe I'll show you another day." Mycroft looked at the two back and forth.
"Well I'm going to go little brother. Have fun with Aniese here." With that he walked out the door. When they heard the door close Sherlock jumped up and walked towards Aniese. He put his face close to hers, looking into her eyes. After a while, with Aniese not moving a centimeter, Sherlock backed away and smiled.
"Okay good. Now Ms. Harts, what shall we do. I'm bored." Sherlock looked at the girl, thinking she could give an answer.
"Hell if I know Sherlock. What do you usually do when you're bored." Sherlock thought for a while.
"Solve cases." Aniese looked at the man wit a blank expression.
"Well lets look for a case Sherlock." With that Aniese picked up her phone and they began looking for cases.