Thanks, let's write that down
One way to deal with clients, with criticism, and with feedback is to not insist on resolving it in the moment.
Taking feedback doesn't have to be the same thing as resolving feedback.
It's tempting to challenge each bit of criticism, to explain your thinking, to justify the choices. This back and forth feels efficient, but it fails to deliver on a few fronts.
First, it makes it more difficult for the client to share her truth, to feel heard.
Second, it escalates the tension, because it's almost impossible to successfully resolve each item in real time.
If you write it down, you can accept the feedback without judgment.
And then, after it's all written down, after the feedback is received, people can change roles. You can sit on the same side of the table, colleagues in search of the best path forward. You can rank by expense, by urgency, by importance. You can agree on timelines and mostly, say, "what do we do now?"