If you do not suspect nausea or constipation, then I think Sadie is telling you she'd like more greens in her diet. You can just lightly steam them or cook them and throw them in with whatever she is eating now. Cruciferous veggies (broccoli, kale, brussel sprouts, collards, cabbage etc.) should always be cooked.

I think it'd be good if you could reduce this excessive grass intake somehow. I say that because when you are off your property you are not going to know what has been sprayed on the grass and it'd be better if she was not in "cow mode" LOL.

I also think this change is worth mentioning to your vet at her next visit....while grass consumption in and of itself is not abnormal, a sudden change is always worth mentioning.