In Moxley v. Title Ins. & Trust Co. (1946) 27 Cal.2d 457, parents created a trust providing for the support, care, and education of their then 15-year-old daughter until she reached the age of 35, at which time the trustees were to transfer the trust estate to her. (Id. at pp. 459-460.) At the age of 26, the daughter brought an action to terminate the trust, alleging the trustors intended to terminate the trust earlier if necessary to relieve her from undue hardship and unexpected contingencies. (Id. at pp. 460-461.) The court applied several general principles. "Ordinarily, the function of the court with reference to active trusts is not to remake the trust instrument, reduce or increase the size of the gifts made therein or accord the beneficiary more advantage than the donor directed that he should enjoy, but rather to ascertain what the donor directed that the donee should receive and to secure to him the enjoyment of that interest." (Id. at pp. 462-463.) "Except under circumstances not shown here, courts cannot substitute their judgment for that of the trustor." (Id. at p. 464.)