Lady has had HGE three times.
Did your vet tell you what CeCe's packed volume was? Subq fluids generally aren't enough unless her packed volume was borderline HGE. Most times they need to be hospitalized and given IV fluids.
Here are a couple of articles on HGE:
Canine Hemorrhagic Gastroenteritis (HGE) ~ Pawprints and Purrs, Inc. Hemorrhagic Gastroenteritis (HGE)