I'm pretty sure this has been beat to death, but I have tried all the most obvious things.

My daughter bought a 99 accord about 2 months ago. The previous owner said she had
brake light issues. It would blow the fuse about once a month. Since then she's now having
to replace the fuse everyday or more.

I have checked the Brake fault sensor pins, the wiring plug behind the seat and replaced
the pedal sensor. I am out of ideas. Is there something else I can check that doesn't require
disassembling the entire car?

Currently all the lights are working (brake and turn) but the brake fault idiot light is on and
the turn signal light flashes fast.

 

Turn signals flashing fast is usually from a bulb being burned out. But you say they all work...

That makes me think something's screwed up in the actual lamp cluster back there. Look for wires with worn insulation. Remove the bulbs & look for the contact tabs being bent or broken or touching the neighboring bulbs.

 

Which fuse is blowing? Fuse #47 20A in the engine bay fuse box, or fuse #9 7.5A in the driver's side fuse box?

The turn signal and brake light circuit are separate, but do share a common ground (G601).

Ground 601 is located below the driver's side tail-light and should have several black wires going into it. I'd disconnect that ground, clean the bolt and eyelet with a wire brush or sandpaper. Then reattach.

 

engine bay stop light fuse and I will go check the ground.
*EDIT* Ground is solid with no corrosion.

 

I've had grounds that looked good, but still required cleaning. Likely not your problem, but definitely a quick fix.

The next thing I would do is unplug the connectors to the failure sensor. Hit the brake pedal to see if you can get the fuse to blow. This will help determine if the short is before or after the brake failure sensor.

 

Got any rust around the rear wheel wells? My Accord, like many others rusted there. Water got in and collected inside the body behind the wheel. The brake light wires and a connector were submerged in the water, shorted, over heated, etc and melted the connector causing a permanent short. When I stepped on the brake pedal, the dash lights would come on. Depending on which connections short out you could get different behavior. On the right side of the car, the connector is attached to the body at the bottom of the chamber so it gets wet first.