It could be a red ant bite.

First of all when was she bred, they carry for 63 days and yes they will get a discharge. Has she gone to the vet for a exray to see how many pups and how big their heads are,they can measure them to make sure the mom wont have a problem with a delivery.

Most likely she is in heat.

Nice trays of all kinds of fresh fruits,strawberrys kiwi,mango, grapes.Also a nice cheese and cut up sausage station would be nice with assorted crackers.Shrimp platters are always very good too.You could also set up a small dessert station.