If she "took" in March, she should be very close. From my donkey foaling experience, she should be bagged up some, watch for the teats to engorge and wax up, the vulva will get a little slack and elongated, she may urinate and have a bit of diarrhea before foaling. She'll roll some too and hold her tail out a bit. Keep an eye on her from afar; they can delay labor if they suspect you are watching too closely. They usually find a time when no one is around, like between 1 and 5 AM, though some of mine don't mind my hanging around to watch, but they know me well. After the foal gets up and the cord breaks, use some 7% tincture of iodine on the navel (I use a cut-down papercup). Once up, the foal should start looking for dinner. Equines should expel the afterbirth within 3 hours, I believe. (Sorry, more than you asked, but I got on a roll!) Good luck with the foaling, they usually do just fine!