Ashley felt bad for asking on that specific day. Since it was her birthday and he considered her as one of his nicer masters, Kreacher would feel obligated to follow through with her request but she had to get Slytherin’s locket from him as soon as was possible. She figured that she was bound to perform Tom’s ritual sometime during the upcoming school term. She wasn’t aware when the breakout was scheduled but the Dark Lord had informed her that it would be soon, most likely before the year ended. After that catastrophe, the Order and Ministry would be on high alert. Tom would undoubtedly rush the ritual, needing his full power then. Ashley had to gather the Horcruxes to ready herself for that moment. She already had two in her possession (excluding herself, of course). The diadem was at Hogwarts and the cup would be sent to her once Bellatrix was available. All that was left was the locket.