Nothing in RCW 6.32.250 shall forbid execution upon the income of any trust created by a person other than the judgment debtor for debt arising through the furnishing of the necessities of life to the beneficiary of such trust; or as to such income forbid the enforcement of any order of the superior court requiring the payment of support for the children under the age of eighteen of any beneficiary; or forbid the enforcement of any order of the superior court subjecting the vested remainder of any such trust upon its expiration to execution for the debts of the remainderman.