Yes, BUT she would have access to your complete Amazon account and her Alexa app would mimic yours, so if she set an alarm, or did anything on the Alexa app it most likely could affect your Echo, although, say your name is xFlip, it appears in the Alexa app as xFlip's Echo, and a second Echo registered in your name would appear as xFlip's 2nd Echo and both of you would need to pay attention to the Echo you are programming or adjusting. A hassle fraught with issues, and for this and other reasons, I would not do this.