That is a close call! Realistically, there is a statistically significant probability that sensha-do participants would be killed or severely injured when turned out, by the projectiles being fired or by blast/fragmentation from the explosions.
I'm thinking that the wind/pressure sheer of the huge mass of the projectile so close to her would cause damage regardless of whether it hits her or not. I imagine it would very likely burst her ear drums, and possibly even cause a concussion.
It's been a while but didn't this happen in the first episode?
Yeah, I know, I thought so too. It's the scene @ 03:40 in episode 1. However, it's just the camera zooming in on Miho's face, giving one the impression that the tank shell is headed straight for it. However, the same exact scene in episode 4 @ 05:01 it shows the after-effect, namely that the tank shell just hits a bit behind them and to their left.
On the other hand, after Saori scolds her to get into the tank because she can't be hit, I could have sworn that she got a crazy look in her eyes as she smiles and says not to worry since getting hit is unlikely. But I checked again @ 05:21, and although she does smile talking about something that would scare most people, it's not really a crazy-eyed smile either.