Work schedule

So maybe u don't agree with me, that's fine, plz keep negativity to yourself...but i feel like it's very unfair I have to work every weekend. Literally Friday Saturday and Sunday 3 pm to 11 pm. While my other co worker gets Saturday and Sunday's off (she works Friday morning) I understand she's been here a little bit longer than me and there's "seniority" which I think is complete BS. I feel like we should be able to take turns, each of us works every other weekend. Should I talk to my boss about this or just keep my mouth shut?