All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
If you had divorced your wife after having consummated the marriage with her, then you are obliged to pay to her the delayed dowry agreed upon at the time of the marriage contract as it is a debt for which you are liable. Therefore, if you had not paid to her the delayed dowry, it is her right to ask you to pay it to her and you are obliged to do so as already discussed. However, if the marriage contract is agreed only on a dowry of 15,000 pounds which will be given at a delayed period to her, and you already gave her this amount at the beginning, then she has no right to ask you anything else as you are only obliged to pay her 15,000 pounds and you had already done so.
Allaah Knows best.