I am going to just repeat what Scully said.
You broke the ice and were brave enough to start this conversation. You have to go back and have some more of that conversation. "Grandma planning to come isn't a reason for me to stop having the same problems that are holding me back......
Am I old enough to get a driver's licence? No.
Am I old enough to vote? No.
Am I old enough to open a bank account without needing parents to co-sign? Probably not.
Am I old enough to get married? No.
Am I old enough to join the military? No. I haven't even registered for selective service yet.
Am I old enough to sign a contract? No.
I will be ready enough when I am ready enough."