Does Islamic law permit me to speak with my elder sister so that she may inform her husband of my desire to marry his relative who proposed to me, in order to address my mother's repeated refusal of all suitors without consulting me, despite my continuous thoughts about sexual matters and my fear of falling into indecency?

The default is that a woman qualified for marriage should not be delayed, especially if a suitable suitor comes to her, because of the Prophet's (peace be upon him) saying: "If there comes to you one whose religion and character you are pleased with, then marry him." And his saying: "Three things should not be delayed: prayer when its time comes, a funeral when it is present, and a single woman when a suitable match is found for her." There is no requirement in Islamic law to delay the marriage of the younger sister until the elder sister marries. The marriage of the younger sister might even be a cause for the elder sister's marriage. There is no objection to the sister's husband proposing the matter to the young man who previously proposed, with his conditions.