^I can't tell if that's a genuine question or trying to throw shade at her statement. In case it's the former: The 16 is clearly a typo. The 6 is directly below the 9 on a number pad, plus she already might have been thinking about 2016, which is stated on the next tweet. She was 19.
If you're trying to imply she's unreliable because she mistakenly stated two different numbers I'm gonna have to adjust my answer.