Sounds like she’s genuinely interested in learning more about Linux from you, and also is into you. The “sorry we didn’t get more done” was just cover since you didn’t make a move towards next stage.
If you like her, I’d say do another hangout, you try to keep it more fun and conversational, and if she reciprocates that vibe again, then confidently make a move towards next steps. Something like “I really enjoy hanging out together, want to get dinner Wednesday after work?”