Apparently it can take up to 2 hours after consumption for alcohol to enter your bloodstream https://www.driverseducationusa.com/resources/alcohol-absorption-in

Apparently it can take up to 2 hours after consumption for alcohol to enter your bloodstream https://www.driverseducationusa.com/resources/alcohol-absorption-in-your-body/ https://www.driverseducationusa.com/resources/alcohol-absorp... so if she had a drink immediately before leaving presumably her BAC could be higher an hour later?