Silly, Really Silly question . . . .

She drinks fyn,
And it isnt the treats as she's had them ever since I've had her and thts 3 years x

What does the vet say about her poops? Is it still the same? Maybe you need to restrict her turnout to that paddock. A couple of hours a day and then put her somewhere "less lush".

Just as an afterthought, does she have any new stresses in her life?

Earlier this year she lots alot if not all of her horsey friends tht she hacked out with, n I've just met sum1 new tht I ride with n ther all mares, all very kicky and in season at the minIt.
So thts probley it
I noticed its started to get harder just lately.

One horsse at my old barn had that. She had runny poo too.