I cannot lend you any of my ships for the venture; Philip would hear of it,' she whispered over her shoulder; 'but as much guns and powder as you ask, if you do not ask too--'Her voice shot up and she stamped her foot thrice. 'Louder! Louder, the music in the gallery! Oh, me, but I have burst out of my shoe!
This is from "Gloriana" in Reward and Fairies by Kipling.
I am glad if some one kindly teach me what "I have burst out of my shoe!" means.