I've noticed for the past couple of days that occasionally when braking the parking brake light comes on, and the owners manual says it's also a brake system warning light.
I checked the brake fluid and it's not quite low, but not really full either so I'm not sure if that would be the cause. I read on another thread that it could be sensors, but I think that car had been in some accidents and mine is pristine

Is it worth just replacing the fluid, throwing new brake pads on, upgrading the brake lines while I'm at it, and hoping the problem gets resolved?
I don't think any brake maintenance has been done, so it's probably due anyways (2014 frs).
Any advice is welcome