Try doing a few very aggressive braking events with the vehicle. But dont come to a complete stop. Then keep rolling and get back up to speed and cool the brakes down. Do this a few times.
What happens is people get brake pad material build up on their rotors. Even if they stop moderately. You come up to a stop sign, with the brakes applied, and stop completely. The pads and rotors are hot and material transfers to the rotor.
Once you stop, slowly roll a little to get your pads to not sit in the same area on the rotors. If they cant sit in the same spot, they cant transfer material to one spot. Less build up in that one spot, less braking vibrations and shaking.
IMO, people change rotors way to much.
If that doesnt help, then Id look elsewhere like suspension.
I used to race cars. I never had any shaking in the brakes, until the rotor actually would crack or break because of the heat. The rotors would glow red during almost every race. Pads would have to be replaced often, but rotors didnt stay in the same spot long enough to build up pad material. And if they did at the end of a race, the build up would be gone at the first application of the brakes during the next race.
The brakes in any vehicle my wife drives always shake. Because she wont slowly rotate the rotors at a stop. I have actually gotten it through her head now, but she doesnt always do it. I got take whatever she's driving and beat the heck outta the brakes for a bit and its all good until she does it again.