Final answer:
A beneficiary is the term for Jill's sister who receives her possession in the will.
Explanation:
A beneficiary would be the term used to refer to Jill's sister who is set to receive Jill's possession, the sound system, as outlined in the will. In this context, a beneficiary is someone who benefits from a will, trust, insurance policy, or other form of inheritance.
For example, if Jill's will specifies that her sister inherits her vintage record collection, then her sister would be considered the beneficiary of that specific asset upon Jill's passing.
Understanding the roles and terms associated with wills and inheritances is crucial in estate planning and asset distribution.
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