(CNN) -- In the wake of her cancer diagnosis, Valerie Harper is staying firmly in the present.
The 73-year-old actress, who revealed in March that she has terminal brain cancer, told reporters on Thursday that she's been staying busy, including working on a "Mary Tyler Moore" reunion episode for the TV Land comedy "Hot In Cleveland."
"Working on the show has been great," said Harper, who is still beloved for her role of Rhoda Morgenstern on "Mary Tyler Moore" and its spinoff, "Rhoda."
"I don't have a lot of bad symptoms, and they may be down the road, but I'm not thinking of down the road -- I'm thinking just about today," she continued. "And I'm thinking of this moment, and getting my lines right so I support my fellow players and serve the audience, who are going to see this really funny show."
TV Land has announced that Harper will be joined by her former co-stars Mary Tyler Moore, Cloris Leachman and Betty White, who stars on "Hot In Cleveland" along with Valerie Bertinelli, Jane Leeves and Wendie Malock.
In the episode, which is set to air this summer during the fourth season of "Hot In Cleveland," White's character, Elka, will try to get her old bowling team back together along with Mamie Sue (Georgia Engel).
Their group, the Gorgeous Ladies of Bowling (or GLOB) includes Elka, Mamie Sue, Diane (Moore), Angie (Harper) and Peg (Leachman). The team fell apart years back after a championship season.
Although they're playing different characters, the old chemistry is back in effect, Moore said.
"We still are ourselves, and no matter where you put us, we're going to continue to be ourselves and interact as only you can when you've been together for a long, long time," she said. "Almost any scene we ever did, we could look into each other's eyes and be comforting and uplifting for each other."
Their time together was filled with laughter rather than tears, Harper said, and White noted how positive Harper has been.
"Well no one can tell you, isn't it true?" Harper responded. "... No doctor in the world can say (whether it will be) three months, six months. They can say that's what our experience is, but every case is different. In some people, it's five years, it's 13 years. It's interesting."
Unlike other shows, the "Mary Tyler Moore" crew is a cast that still has a bond, White added.
"We're all very grateful for the fact that we love each other and we've always gotten along. Just think if had been one of those shows where we don't speak. That wouldn't have been any fun!" the 91-year-old star said. To fall in once again with a cast filled with women, after her time with "Mary Tyler Moore" and "Golden Girls," has been a treat.
"(We're) a group of women who aren't just making it work, we adore each other!" White said. "And if you wind up with these kinds of friendships that are lifelong, there's nothing like it."