What is the ruling when one sister acknowledges both a brother and a sister?

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If one of the four sisters acknowledges a brother and a sister, the acknowledgment scenario is based on seven parts, and the denial scenario on six parts. Multiplying these results in forty-two parts. She retains one share in the six-part scenario and has seven shares in her possession; thus, one excess share remains for them both. If all four sisters acknowledge both, four excess shares are due to them. If those acknowledged are in agreement, they divide the four shares by three. If they dispute, the brother receives nothing because he acknowledges that he is not entitled to two-thirds of the excess. The remaining portion belongs to the sister because she claims one-fifth of the two-thirds. If the brother denies the sister's claim without the sister denying him, her denial is disregarded due to the acknowledgment by the known sisters. If the brother denies the sister, and she does not deny him, it is possible that the acknowledged portion belongs to her because he acknowledges having no right to the two-thirds, and she claims this excess from the two-thirds. Alternatively, it is possible she is only entitled to one-third of the four shares because of her acknowledgment to the brother. The former possibility is preferred, Allah willing.