I think there is definitely a possibility, BUT it will take a very very long time. I think what may help a lot is for Aarti to help Payal and Palak win their dance competition, like Yash helped Ansh. This may prove to Gayatri that Aarti does care for the girls, and though she may not love her immediately, it may soften her heart a tad bit.
Gayatri is not evil. I know many will not agree with me in this forum, but I think the truly evil and selfish character is BUA. Sr. Scinidya and Gayatri, despite their negative thinking and actions, still care for their children's happiness. It may be twisted and unfair what they do to get their way, but they still have their children's happiness in mind, whereas Bua hates everyone in the family. If she is rid of Bua's presence, and if Aarti's kindness softens her heart, I think there's potential for Gayatri to become a positive character in the far future.
After all, if Dadisa of Balika Vadhu could become a positive character, anyone could.😆