If you really weigh 110 pounds, 4 shots of tequila could get you to 0.165% blood alcohol concentration. If you are down to 105 pounds, then they would get you to 0.173%. If you only weigh 100 pounds, then they would get you to 0.182%. If the drinks were slightly more generous than the recipe calls for, in which case you had 5 drinks, then even if you weight 110 pounds, it would put your BAC over 0.2%, which is the level at which you can expect to do some puking.

Some sources say "vomiting usually occurs" at 0.12% (http://www.lmu.edu/Page25066.aspx)

This newspaper reports a girl hospitalized with vomiting and a BAC of 0.127%: http://nevadasagebrush.com/blog/2011...with-high-bac/

A website says "vomiting common" at 0.13-0.15% (http://www.lifeloc.com/measurement.aspx)

Doug