Perhaps her sister has reached an age in which she feels in competition for the attention that is available in the family. Consult your pediatrician for a thorough physical examination. Your experience of her independence may have caused you to overlook the ways in which she needs to depend on you. Let her know these times with you and with her Daddy will come up predictably. If she feels she has special time to look forward to with you and with her father once a week, she will soon be able to experience herself as special.
Every child needs to feel unique.
Sometimes dual work schedules do not make room for children's needs for individual time with each parent. Sometimes our lives become so scheduled and hectic that we forget to slow down enough to make room for feelings. She will feel understood. And she will learn inner patience from your patient treatment. Do not expect your daughter's behavior to change at once.