Answer:
Work in her focus abilities.
Step-by-step explanation:
Being focus is mandatory if Nina wanna be a effective and attentive listener. There are several things she could do to improve this. Turning off the smartphone, having no conversations while the speaker is talking, taking notes will help to pay more attention, follow speakers eyes and body language, all these actions can help Nina to improve her listening skills.
Moreover, having some personal goals before the seminar make a big difference, because she can consult them during the seminars.