She became a U.S. federal agent and she has extremely fast healing ability because the G virus.
Yup. To go into a little more detail, immediately after RE2 Leon, Claire, and Sherry see some federal agents (presumably coming to investigate Raccoon) and Leon tells Claire to run off since being taken into custody would stop her from searching for Chris. She does so, and continues into her story in Code Veronica. Leon and Sherry are picked up by the agents, and Leon is offered a deal to join the government as an agent dealing with bioterror, leading to his stories in Darkside Chronicles, RE4, and RE6 (and the CGI movies, I guess).
Sherry seems to have gotten a bit of a rough deal, though, as she was monitored and studied by the government due to having the G-Virus (and its vaccine). She apparently was allowed to see Leon and Claire (presumably post-CV for the latter) regularly, so she had some happy moments (in RE6 she essentially calls them her best friends or family). Eventually once she got older she was allowed to train and join up with the government, leading to RE6.
(There was some stuff in the Wesker Reports about Wesker getting a hold of Sherry at some point, not sure if that's still canon or was just more about him having access to information on the G-Virus)
Also I would be remiss if I didn't mention the SD Perry novel canon, where Sherry is adopted by her aunt, who is the scariest lawyer in the world and is apparently capable of fending off any subsequent attempts by Umbrella to kidnap her.