Valerie Harper, who played the comic relief character, Rhoda Morgenstern, on "The Mary Tyler Moore Show" announced she's been diagnosed with terminal brain cancer. People Magazine reports she could have as little as 3 months left to live.

The "Rhoda" spinoff star told People she has leptomeningeal carcinomatosis, which is a condition that happens when cancer cells reach the liquid membrane around the brain cortex.

Numbness around the jaw while she was rehearsing for her one-woman show "Looped" on January 11^th, alerted the actress something strange was going on with her health.

"(I) was rehearsing away, and then it was as if I had Novocaine," Harper told Good Morning America in a late January interview. "I thought, what the heck is happening to me? (I) went to the hospital, and they couldn't find much of anything."

Harpers new mission for the time she has left is to raise awareness and resources for the relatively obscure disease.

"This is a really complicated condition," Dr. Jeremy Rudnick, Harper's neuro-oncologist told People Magazine. "The spinal fluid is a collection of fluid that's being circulated (through the brain) kind of like a sink. The fluid itself is growing cancer cells, so they are multiplying in there. Those cells start to coat the brain."

Harper was diagnosed with lung cancer in 2009 and is determined to make the most of the time she has left to live. She's now a month into chemotherapy, but doctors are predicting the television star only has a few months of life left.