Wondering About Muslim Holidays – How to Be Supportive?

Salaam! So I'm a teacher, and one of the teaching assistants I work with is Muslim. I really want to make sure she feels comfortable and included. I know there are different kinds of days in Islam-some are for celebration, others seem more about quiet reflection or remembrance. I'm big on marking special occasions, so I was hoping to learn: which days would be appropriate to say something kind, or maybe give a small card or gift? Is that even a thing folks do? Any guidance would mean a lot. JazakAllah khair for your help!