Contemporary scholars, especially the feminist ones, differ as to whether the story represents Mary as the champion of women because she is commended for not being in the kitchen and Jesus' rebuke to Martha only reinforces the traditional role of women as domestic servants. Rubbish!
The fact that there is no agreed interpretation suggests often enough that the meaning is deeper. My interpretation is simpler and backed up by other Scriptures. Simply put, Jesus does not carry forward secondhand messages. "Tell my sister..." is a request to pass on a message. Jesus will always answer our prayer to change our ways. He does not seem as keen to answer our prayer to change other people. "Lord, do you not care that my sister is leaving me to do all the serving all by myself? Please tell her to help me."
Does it not seem consistent with your experience that our relationship with Jesus is personal. He wants to change us one at a time. Secondhand messages are not passed on. If you have a message fro your sister, pass it on yourself!
Compare with Lk 12:13 "Master, tell my brother to give me a share of our inheritance." Again, Jesus does not pass on messages! We will see this passage in two weeks.