How can i help my girlfriend learn spanish, as a fluent speaker?

I am a fluent spanish speaker. I was raised in a Colombian and Mexican household and spent a lot of time with family. I’m currently learning Portuguese, and it’s sort of helping me understand my girlfriend’s dilemma however it’s still foreign to me honestly.

With that being said, my girlfriend is of Mexican descent but she does not know the language. She wants to learn and understand the culture, and she wants to travel and see my family. She is putting in effort (i.e. Duolingo), however it’s not really helping her. I’m trying to help her with the culture aspect which is already incredibly difficult, but I wanted to help her learn spanish since it’s something she’s been wanting to do. I don’t want to be rude and say apps like Duolingo don’t really help retain anything, much like modern education doesn’t incentivize learning but instead memorization but I truly don’t think they are effective at all.

Anyways, how can I help her? What are the most effective ways to learn spanish? Is there anything I can do to make things a little easier for her?