I agree with a few of the other responses: get her involved, by asking her to do a read-aloud and asking her to do specific things. Pair her up with a table group or one specific student who has difficulties with reading or comprehension. Maybe she could read with a child who has difficulty reading.
Remember that this is a "field experience" will help you to get her involved.
And of course, ask her what she'd feel comfortable doing. She may have some specific tasks that she's curious about doing.
Last, but not least...as always, let her know she is welcome to jump in and help the students during lessons.
