Horn_in_Aggieland said:
https://www.txdot.gov/inside-txdot/division/traffic/safety/sober-safe/intoxication.html
When am I legally intoxicated?
You are legally intoxicated in Texas when your blood alcohol concentration reaches 0.08%, but you are breaking the law as soon as drugs or alcohol affect your driving or flying or boating ability.
What did she have with the lemonade?
Unless the law has changed, intoxication is an issue of FACT for the jury to decide. (No, I don't have the citations but I served on a DWI jury in Dallas County once; you'll just have to take my word for it). BAC level is EVIDENCE of intoxication but can't actually prove it as a matter of law.
With that said, perhaps there's been some changes. I know legislators go BSC when it comes to DWI laws. I rarely drink and think drunk drivers should be shot. But I hate how people's civil rights are sometimes just brushed aside in cases like this. Higher courts know all this but allow it anyway.
Bottom line: you get pulled over for suspected DWI, you're going to jail in most counties. The so-called tests are done to create evidence against you, not clear you.