Iris shook her head when Eliot offered to hold the bag, not because she didn't trust him (though she didn't) but because she needed to have control of something, or she wasn't going to be able to get through this in one piece. The last thing she wanted to do was show Eliot emotional weakness, and she suspected she was doing badly enough with that goal as it was.
She nodded, taking his opinion as very reassuring fact, and ascended to the roof floor with no further comment, only growing more grim and expressionless as they climbed.