Abby Lee Miller May Never Walk Again After Cancer Diagnosis, Source Claims

Abby Lee Miller is trying to keep her head up amid a new development in her ongoing cancer battle, sources told PEOPLE Thursday.

"Abby has been trying to stay positive throughout this journey, but it's been tough," the insider said. "She's getting a little stronger every day, but we don't know if she'll ever walk again."

A second source told the publication that Miller "is leaving rehab tomorrow to undergo more chemotherapy. Abby's tough, and she continues to keep her spirits up as she focuses on her health."

The former Dance Moms star was diagnosed with cancer in April after undergoing emergency spine surgery for what doctors initially thought was an infection.

"It was not an infection, it was a type of a non-Hodgkin's lymphoma – it's a type of a cancer," Dr. Hooman M. Melamed, an orthopedic spine surgeon at Cedar Sinai Marina Del Rey Hospital told PEOPLE at the time of her diagnosis.

"We're getting an oncologist involved and we have to figure out what the next steps are as far as chemotherapy or radiation or more spine surgery. Depending on the tumor type, depending on the sensitivity of the tumor – it just depends the type but I feel more than yes, she will undergo chemotherapy or radiation," he continued.

The situation was pretty dire, he added. "If we didn't do something, she was going to die," he explained. "Her blood pressure was bottoming out. She was not doing well."

Since then, Miller has been chronicling her treatments for fans on Instagram, sharing vulnerable moments from her battle with the disease and throughout chemotherapy and physical therapy.

Wednesday, she posted a photo of herself out and about in a wheelchair, captioning it, "Hallelujah! I'm headed to the Mall! I've only been once in 13 long painful months. For a lifelong shopper like me that's absolute torture!!!"

And although Miller's future health is currently up in the air, it appears that she will be returning to Season 8 of Dance Moms, based on the casting call for the upcoming return of the Lifetime show.

"Abby Lee Miller has launched some of the most successful careers of this generation!" read the posting on dancemomscasting.com. "She is currently casting NEW talent for Dance Moms. Does your daughter/son outshine their competition? Are they destined for greatness? Would they love the opportunity to train and compete as a member of ALDC? This could be the fast-track to stardom your kid deserves!"

Best of luck to Miller in this time!

Photo credit: Instagram/Abby Lee Miller