Is a notice of appeal valid when it is derived from an order denying a motion to amend the complaint?

Plaintiff defended the validity of her notice of appeal based on the exception applied in Dominguez v. City of Alhambra (1981) 118 Cal.App.3d 237, 241-242 (Dominguez). In that case, the notice of appeal was taken from an order denying a motion for leave to amend the complaint. While that order ordinarily is not appealable, the court applied an exception and held it was "in effect, a final determination of appellant's rights in her capacity as administratrix of the estate. [Citation.] In that capacity appellant was a separate party as to whom there was no issue left to be determined, and the order operated as a final judgment for purposes of appeal. [Citations.]" (Ibid.)