Do your older kids say that to you?
I agree that the little ones get babied for much longer but I make a true effort in not distinguishing between the two. I give them the same gifts, clothes, attention and chores but my older daughter occasionally says that to me and it stings me.
As a older sibling - I felt like that my little sister got more attention (until my mom had my little brother). I even conducted a test at age 7 to prove that I was right… 
I wonder if it’s ploy of getting out of doing chores or getting attention … opinions?