First, unless you have a prototype, you shouldn't be worried about this. It's this type of stuff like LLC v. C-Corp that startups focus on and they shouldn't.

First, unless you have a prototype, you shouldn't be worried about this. It's this type of stuff like LLC v. C-Corp that startups focus on and they shouldn't. Second, think of founders as your YC group (if you were to apply). If she would be part of your YC group (the group that is the core of the company at this stage), then she's a founder. Usually being a founder also implies a class of stock. Third, you should always hire people smarter and give them compensation that makes them happy and aligned with your company. If she's worth it to moving the company foward, then go ahead and call her "founder." She's got to be in it for the long haul though. Meaning getting paid peanuts banking on those options/equity.