Jewelry Bonney wasn’t impersonating anyone to get into the Reverie, that was her true identity. The person the guards recognized her as was of the elderly Queen Dowager Connie, of the Sorbet Kingdom. That’s who I think she actually is.
I think Jewelry Bonney is actually an elderly queen of a kingdom, and she uses her Devil Fruit to de-age herself and pose as the pirate captain Jewelry Bonney. This is why she’s constantly eating, she’s taking advantage of her power to spoil herself in ways that she regrets not having done when she was younger. Basically, she knows what it’s like to be old and frail, so she’s living out her dreams to be young again. This is also why she never gets fat, because her young body isn’t actually real, it’s just a de-aged version of her actual old body, anything she does to it is temporary.
Additionally, Connie is the elderly queen of the Sorbet Kingdom, which was also the kingdom Kuma was stated to have been the tyrant king of.
I believe that Jewelry Bonney is Bartholomew Kuma’s mother. Kuma used to be a tyrant until the Revolutionary Army took him down and he had a change of heart and joined them. Kuma later joined the World Government undercover for the Revolutionary Army as a Warlord of the Sea.
This is why Bonney was crying when she was watching the Paramount War, it was in response to seeing what the World Government had done to her son. She saw him fighting Ivankov, one of his friends from the Revolutionary Army, and she saw the squadron of Pacifistas in his likeness (notably, she was one of two Supernovas not to see either Kuma or a Pacifista on Sabaody, only her and Bege never saw one).
*Theory by PushoverMediaCritic