We find lots of different pre-farrowing "moods" in our sows. Going a bit off their food does occasionally happen, but providing she's still eating 2lb, would not worry too much.
First rule of any pig not eating is check their water - the "dry" feed needs lots of water - probably not relevant in your case as she's eating some, but would be worth checking that she has enough water and has found it in her new environment.
If she is just on sow pellets - would be worth supplementing with something to see if she's just in a funny mood - try some apples , quite often they'll eat fruit when they are not in the mood for dry food.
But unless she really goes off food, would not really worry.