They seemed like standard catty rivals. But they found some common ground after bonding over Synch's death. Then it moved to a frienmies deal where they still barbed, but the true animosity was gone.
When they were both in Wood's X-Men, he reset Jubilee to outright hating Monet at the mere sight of her. Meanwhile, Monet was extra nice and even told her how cute Shogo was. Given how Monet was somewhat nicer & toned-down in that run, it made Jubile'ss attitude even more jarring. Monet was even the one to reach out to her when she was captured and let her know they all loved her.