Hmmm, she never had regurge problems before she laid her clutch? It's a slight possiblility that she is calcium-deficient since laying her eggs and so she doesn't have nice smooth muscle motion in her gut which is causing occasional regurge. It's a simple blood test that would find that out, so if your vet is doing other studies in his detective work, ask him to add a serum calcium level to it.
My guess is cohabitation stress though, possibly combined with parasites.
The Zombie Mama is here!