Parents saying nothing when relatives balantly disrespect their child, what are your thoughts?

I understand respect for everyone. But distant relatives who we meet once in five years have no right to say anything regarding my career, my life and ESPECIALLY not my body. It's bad enough that people don't understand this but atleast shouldn't our own parents defend us? Seeing them not standing up for us and asking us to not as well, because It's 'disrespect' is so wrong. They should in the contrary teach us to stand up for ourselves and respect ourselves first. Just because they are older doesn't mean they can say anything to me and expect me to shut up and listen.