Indiana Code Title 30. Trusts and Fiduciaries § 30-4-2.1-2

Sec. 2. (a) Except as provided in subsection (b), in construing a trust naming as beneficiary a person described by relationship to the settlor or to another, a person adopted before:

shall be considered the child of the adopting parent or parents and not the child of the natural or previous adopting parents.

(b) If a natural parent or previous adopting parent marries the adopting parent before the settlor's death, the adopted person shall also be considered the child of the natural or previous adopting parent.

(c) A person adopted by the settlor after the person becomes twenty-one (21) years of age shall be considered the child of the settlor.  However, no other person is entitled to establish the relationship to the settlor through the child.