Paul Aiken, Daily CameraBoulder teacher Cara Mentzel gives a high-five to her student, Lila Robbie, during class at Foothill Elementary on Oct 6. Mentzel, sister of Broadway star Idina Menzel, penned a memoir, “Voice Lessons: A Sisters Story.” “Is this good enough?” The question raced in Boulder elementary teacher Cara Mentzel’s mind as she stretched to reach decades back into memories she shared with her big sister — Broadway, TV and movie star Idina Menzel. “Do people care?” she wondered. Yes, her husband, Mark, told her — put in the time and you’ll be fine. Related ArticlesOctober 22, 2017 Martin Truex Jr.