make sure she's warm, if she's clipped put a rug on. the warmer, the better to keep the central heating working. Altough not that warm she sweats. Also, give her something to do while in  the stable, for example 2 hay nets with small holes at each end of the stable to keep her chewing and moving. Mollichaff showshine is really good too, with high fibre nuts and sugar beet. Hope this helps..i'd try it anyway as its a cheapp way of feeding but really does work.

p.s, if she isn't clipped yet, i'd leave her without a rug as the more natural, the better.