(a) General rule.--
(1) Subject to paragraphs (2) and (3), in the absence of a contrary intent appearing in the instrument creating a power of appointment or, in the donee's instrument, exercising the power, an exercise of the power of appointment in favor of any of the following, whether designated by name or as one of a class, shall not fail if the appointee is not living at the time the appointment becomes effective:
(i) A child or other issue of the donee.
(ii) A brother or sister of the donee.
(iii) A child of a brother or sister of the donee.
(2) Paragraph (1) applies if:
(i) One or more issues of the appointee are living at the time the appointment becomes effective.
(ii) The issue under subparagraph (i), per stirpes, are objects of the power.
(3) The property appointed to the deceased appointee shall pass per stirpes to the appointee's issue living at the time the appointment becomes effective, but the appointment to a brother or sister or child of a brother or sister of the donee shall fail to the extent the property would pass to the spouse or issue of the donee if the appointment were to lapse.
(b) Lapsed share of residue.--In the absence of a contrary intent appearing in the donee's instrument exercising a power of appointment, if an appointment of an amount or share of the residue of the property subject to the power fails, the amount or share shall pass to the other appointees of the residue of the property subject to the power, if any, in proportion to their shares in the residue of the property subject to the power.