All that I can remember of this dream is that I was probably not in the dream, but I am not sure.
The dream involved the television show Game Of Thrones (Season 7) and it took place during the day.
Cersei was doing this to send a message / make a statement that she is able to pull off an attack like this (because her intelligence network has improved) and is willing to go there in person even while allegedly pregnant, to show off, to prove herself, to hopefully gain some intelligence from and about the Dothraki (by fighting and kidnapping some to torture and / or bribe for information) and about the defenses at Dragonstone, to annoy and disrupt and weaken her enemies, et cetera.
Cersei and a small army sailed to Dragonstone in ships when Daenerys and her dragons were gone somewhere, and they attacked Dragonstone by surprise with siege weapons from their ships hitting some buildings and damaging parts of the island and destroying some ships / boats and killing some soldiers.
Some of the Dothraki charged toward the beach with their horses to defend the island, but Cersei’s army attacked them with bows and arrows and crossbows and siege weapons before sending a small group of soldiers to escort Cersei on the beach so that they could kidnap some of the surviving Dothraki.
Cersei and her guards walked on the beach, Cersei watched as her guards killed some of the surviving Dothraki and took the rest prisoner, and she stood there smiling and looking very proud of herself.
More Dothraki and members of Daenerys’s army started to charge the beach, Cersei stood there smiling as they approached as her guards warned her that they needed to leave now before it is too late (they could not win the battle if they stayed), and she stalled a bit longer to gloat before boarding her ship with her guards to escape back to King‘s Landing.
Cersei’s hit-and-run attack was a success, even though they only did limited damage, and they sailed away, but I woke up.