That's sad news......did they say what happened? Most often when a mare aborts at that stage of pregnancy, it's either because they missed a twin during ultra sounds, or she had some sort of infection not detected in pre breeding exam.
I've been through that, and it's very emotional & depressing to deal with...if you have any info on the cause, I would be interested to know.
Guess now the baby will be...Indypepper
Best of luck to the mare and her connections that this next pregnancy goes to term