If she is aborting you may want to keep her - and what she emits - seperate from the other ewes. Quite a few of the reasons for aborting are highly contagious and will be passed from the aborted material to the ewes and lambs that come into contact with it, possibly to affect them next year or, in the case of ewe lambs, when they first lamb.
If she does abort and there's nothing obviously wrong with the foetus, you could consider picking up the aborted foetus and getting it to your local Vet Labs asap - if you have some placental material with it and get it there fast they may be able to identify the causative agent if it is one of the contagious ones, and depending on which one it is, you may be able to give prophylactics to the rest of the flock.
Generally we would not do this on a first abortion, only if we start to get several, but I just wanted to let you know that there is that option.
Best of luck
