Green Card for 26 years old daughter

[CIUDADANA15]

Hi, I'm a US Citizen and I want to apply for a green card for my 26 years old daughter. She still has one more year to finish Medical School in the University in Guatemala.

I have a couple of questions:

I understand that there is a waiting time for preference F1 (she falls into that category), any idea of the approximate waiting time? She is from Guatemala.
During the waiting time after having applied, can she travel to the US (to visit), she has a tourist visa B1/B2?

Thank you for your help

[Jot18]

You can check the priority dates on the following link: http://travel.state.gov/contenthttps...checkdate.html
Yes, most likely there wont be any problems traveling while her case is pending.