Don’t bring her inside on her own to eat salad, separating them is stressful but also eating a salad is not enough to stop weight loss, it isn’t the essential fibre she needs and it won’t replace her reduction in hay intake.
She is losing weight because her hay intake has dropped and it is that which needs to be replaced. Hay makes 80% of the daily food intake, veg just 15% so without eating enough hay a huge amount of the daily food needs has been lost whether they eat their veg or not.
She needs to be syringe fed a fibre rich recovery feed or mushed pellets to replace the hay intake.
You need to syringe feed as much as is necessary to keep her weight stable each day - around 40-60ml as a minimum in each 24 hour period (the less she takes at each sitting the more sittings will be needed each day).
If you don’t syringe feed her from now and she doesn’t eat enough hay independently, then her weight loss will very quickly reach significant levels. Remembering 100g weight loss constitutes an urgent situation.