The events of Street Fighter are not tied to actual years -- character birth years were canonically abolished starting with the Alpha series. SFV takes place shortly after IV, and it features modern technology that didn't exist in 1994 like text messaging/Twitter and MP3 players.
SF4 is in 1994, 4 years before ibuki's appearance.
Long-running media franchises have their own way of dealing with time. Batman debuted in 1939, but Bruce Wayne isn't a 100-year-old man. Mario hasn't aged a day since 1981.