I agree, go for the best components you can afford. I got rid of my first road bike after a year because of the poor shifting of the Tiagra/Sora combo (which was then the lowest) and upgraded to Ultegra. It was worth it. I never could shift into the big ring on the triple of my first bike and it always was having issues jumping from cog to cog. That is not good for a fairly new rider. And yes, Trek does have it down for petite female riders. So does Specialized, but they do not have as many options.
2015 Trek Silque SSL
Specialized Oura
2011 Guru Praemio
Specialized Oura
2017 Specialized Ariel Sport