Abby Lee Miller Is Staying Optimistic While Undergoing Chemo: 'She Has Good and Bad Days'

As Abby Lee Miller continuers to recover after undergoing emergency surgery last month, the former Dance Moms star is doing her best to remain positive.

“She is undergoing chemo and has good days and bad days, but overall she’s staying optimistic and looking forward,” a source tells PEOPLE.

Doctors originally thought Miller was suffering from a spinal infection. But on April 18, Dr. Hooman M. Melamed — an orthopedic spine surgeon at Cedar Sinai Marina Del Rey Hospital who has been treating Miller preliminarily – diagnosed her with Burkitt lymphoma, a form of non-Hodgkin’s lymphoma, which is cancer that develops in the lymphatic system.

Abby Lee Miller/instagram

RELATED VIDEO: Abby Lee Miller Has Been Diagnosed with Non-Hodgkin’s Lymphoma

The reality star underwent a five-hour multi-level laminectomy on April 17 that required an 18-inch incision on her back just three weeks after she entered a halfway house following her release from prison for bankruptcy fraud.

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A source adds that Miller will return to the halfway house once she is released from the hospital.