Sherry and the Raccoon City Incident, known simply as "Sherry and the Raccoon Incident" (シェリーとラクーン事件 Sherī to rakūn jiken ) in the original script, is a file in Resident Evil 6.
The sentence where Claire and Sherry are said to lead busy lives is in fact two sentences in the original script. The reasons for both of their busy schedules - Claire working for an NGO; Sherry for the US government - was left out.
It can be obtained in Chapter 4 of Jake Story.
In 1998, William Birkin, father of Sherry Birkin, decided to keep the results of his G-Virus research for himself. His superiors at Umbrella had grown tired of his attitude and sent a commando unit to retrieve the virus for them. The unit's mission coincided with the T-Virus leak that had contaminated Raccoon City. The confluence of the two events contributed greatly to the city's destruction.
Sherry Birkin was also caught up in these events, but thanks to the heroic efforts of Leon Kennedy and Claire Redfield, she was able to survive the incident. Sherry considered Claire to be her new mother after losing both her parents. It was Claire's love and devotion that had the greatest impact on Sherry's development, and Claire's nurturing and compassionate ways have manifested themselves in Sherry's own personality. Sherry and Claire both led very busy lives, but Sherry still made an effort to try and meet when their schedules allowed it.
Below is an e-mail addressed to Claire, but accidentally sent to a co-worker.
I was able to get some days off at the end of next month when you said you'd be in America. I have so much I want to talk to you about. I can't wait to see you!
I'll send Ronny a message, too. I bet he'll be excited to hear you're coming back!
In 1998, Sherry Birkin's father William Birkin incurred the opposition of the top brass by attempting to monopolize the "G-Virus" he himself discovered, and the virus was almost stolen from him by his organization's security service.
At that time, the "t-Virus" which transforms humans into Zombies and is different from the "G-Virus" had leaked outside a laboratory. This was the beginning of the Raccoon incident. Although Sherry was also embroiled in this incident, she met two people, and with their help she survived from Raccoon City, which had fallen into a Zombie panic.
The people were Leon S. Kennedy and Claire Redfield, the younger sister of Chris Redfield. Particularly, following the incident the kind Claire continued to support Sherry, who had grown up without any direct love from her parents, and Sherry came to put more trust in her than a blood relative.
Claire's influence on Sherry was big, and Sherry inherited her motherliness and tolerance. Sherry's house arrest was cleared and she became an agent, obtaining a restricted freedom. Now, although Claire belongs to an NGO and flies around the world while Sherry is a U.S. agent, and they each have busy situations, they display their closeness and spend time together if their schedules permit.
An e-mail addressed to Claire which Sherry accidentally sent to a coworker remains.
"Claire, when you said you were coming back to the U.S. at the end of next month, I got a vacation.
There's a lot I want to talk with you about. I can't wait to see you.
I'll let Rani know. She'll be very happy to hear you're coming home"