42 Pa.C.S. § 7535: Rights of fiduciaries and other persons.

Any person interested, as or through an executor, administrator, trustee, guardian, or other fiduciary, creditor, devisee, legatee, heir, next of kin, or cestui que trust, in the administration of a trust, or of the estate of a decedent, an infant, lunatic, or insolvent, may have a declaration of rights or legal relations in respect thereto:

(1) To ascertain any class of creditors, devisees, legatees, heirs, next of kin, or others.

(2) To direct the executors, administrators, or trustees to do or abstain from doing any particular act in their fiduciary capacity.

(3) To determine any question arising in the administration of the estate or trust, including questions of construction of wills and other writings.