John and Mary were going to get married. In fact, they're getting married today. You were chosen as Mary's maid of honor, and Sherlock was John's best man. You've met John when he and Mary first met, but you've only met Sherlock once he proved he wasn't actually dead. The four of you got along very good. Sherlock might've actually... liked you.

Currently, you were right after following John and Mary down the aisle with Sherlock. There was a bit of free time for everyone to greet eachother and congratulate the newly-wed couple. This meant you and Sherlock had a bit of time to yourselves.