AKA stalking. Malia had politely declined, and that should've been all.
IIRC, public area removes certain pr%ivacy expectations.
Note: Her guards knew better than to intervene.
YMMV.
If Malia were smart, she would arrange to get a room for a few hours a week from Harvard, and establish Office Hours, and then print up a thousand cards with her name, the Room Number, and the times.
If anybody bothers her on the stret or at her dorm, she can just hand out a card, and say that she is busy and can’t deal with the request right at that moment, but invite the person to discuss it with her at Office Hours.
99% of the people who take the card will not bother to show up, but nobody will be able to say that she is not willing to share her time. Her only request would be to do so at a time and place that is convenient to her
Since nobody will show up, it will be a few hours a week where she can sit alone in a quiet room and catch up on her studying, which is something every college Freshman can certainly use.