I want to punish my older daughter more than my younger daughter for a rule that both of them broke. Is that bad?
Why do you want to punish your older daughter more for breaking the rule?
As the older daughter, she should know better than to have broken the rule.
I understand why you're more frustrated with the behavior of your older daughter. As the older daughter, she should understand the consequences of her actions and how her younger sister follows her lead. You should talk to your daughters about making better decisions, and explain to your older daughter that you expect more from her; however, I wouldn't punish her more for the same behavior. She would rightly feel it's unfair and become resentful.
You got it messed up. My younger daughter gave the wrong answers just to annoy me. It had to be done.
That's my point. It would be unfair to punish the older daughter more, but it's OK to let her know you expect more from her because she's older.