Point1-THe family head is Daddaji and naitik's dad is the perfect bharat for his dadaji.so gayatri's husband's support is out of question in controversial matters
Point2-Bhabhima controls the kitchen and the household as she is the badi of the house.so she becomes the saas figure,soall will do what she says.
Point3-In a conservative family like this having a son is prestige issue probably after Naitik was born,gayatri got some right to speak.That is one of the reason why gayatri feels she has to hold on to naitik.
Last but not the least is that Naitik by supporting his mom and viceversa developed an affection which is special,anybody will love to hold on to that relationship.
on the whole,gayatri is not bad but feels that the special bond she shared with naitik will be a thing of the past if akshara gets closer to naitik.she will understand and get used to the fact that her son is married and another person is close to her son as she is.But now all she needs is Reassurance.This is my take on how gayatri character has shaped up with my understanding of living with my saas