Im terrible at interrupting.
I found that if I dont interrupt people, they just talk right over me and dont hear anything I say. They could be talking for hours. I had a boss like that. We would have meetings where it was him talking all the time and we could only ask questions right at the end he got an hour and we workers got like less than five minutes.
So, maybe theres a better way but I havent found it yet. If I waited till my new boss finished what she was doing so I could speak to her, I would be waiting months. By that time, I wouldnt be able to get anything done because its dependent on whether shes free to speak to me.