Oh jeesus Yael, that is tough. I don't need to preach to you, but just because we don't have kids does not mean our time is up for grabs. I'm sorry your family are treating you like this. In their heads "it makes sense."

In my childfree community on Twitter I have several amazing followers who talk passionately about the care expectation falling to childfree/childless females in the family. Sending you the strength to stand your ground and the self-compassion not to allow them to induce feelings of guilt.