The rinnegan awakens by having the some of Indra's and Ashura' s chakra melded into one vessel. Simply mixing uchiha w/senju chakra will not awaken the Rinnegan.You forgot to mention the fact that she will possess BOTH Senju(Uzumaki) and Uchiha blood in her, thus likely giving her the opportunity of someday awakening the Rinnegan and more other potential, much more than even her own father.