Oh no, poor mamma

How long has she still got to go Mrs S ?
I know it might seem cruel, but I'd make her get up and have a walk about (slowly) even if it's just spreading her food around so she has to walk to get it

Keep her moving and don't let her go off her feet - no matter how pittifully she looks at you

Make sure her area is all clear of water/ice - last thing you want is her to slip at this stage.
Birthing won't neccesarily be hard for her (unless the piglets are HUGE - better with big numbers of small piglets for easier farrowing

) but if she's a bit cumbersome and slow make sure there's a creep area and no straw blocking the piglets from getting to it once they do arrive.
HTH & hope mamma's feeling better soon (oooooh, can't wait for piccies

)
Karen x