If you were 4 and now you are 44 then you might be an integer variable. If sister is also a variable, we don’t know when she was allocated. She might also be an integer constant in which case she’s arguably immortal.

If your parents had another daughter in the meantime (or if your older brother became female), “my sister” would still be a valid reference, to a completely different person.

Seems to be a common feature of US politics that words lose their meanings and become distorted into vague aspersions about categories of people, which in practice take on the meaning of “the enemy” or at least “the other”, words degraded so that their main purpose is to divide.