An act like that is what Cersei is banking on..and I think Dany is going to give it to her..unless she has another way of getting Euron's fleet out of the way..it seems like Drogon going to be busy next week. Tyrion pleading with Cersei to surrender.. He had a better chance of getting thru the Mountain instead of her.
Cersei's death will be glorious. I'm not sure who is gonna take her out, but we have options: Arya, Jamie, Tyrion and Sansa come to mind.