Is it permissible for unmarried brothers and sisters to share one Uḍḥiyah (sacrificial animal) with their father and mother in order to be able to give money to the poor in addition to the meat?

A single sacrifice (Udhiyah) suffices for a man and his household members whose maintenance is obligatory upon him, or for whom he performs it as a voluntary act, based on the hadith of Aisha (may Allah be pleased with her) that the Prophet (peace be upon him) sacrificed on behalf of himself and his household. This is also supported by what Malik narrated from Abu Ayyub al-Ansari. Accordingly, if one of you provides for the rest, then the sacrifice is incumbent upon the provider and is waived for those he supports. However, if some of you are financially independent, then an Udhiyah is obligatory for everyone who is financially independent for himself or for himself and others.