Obviously her motive is to compare the two beendnis and to make Jagay aware that Anandi was indeed the best beendini he could get..She might want to show him how well Anandi managed both ghar and the school without giving anyone chance to find fault.. even though DS did find some but thats part of her nature.. DS is sure siding Anandi, indirectly
I agree, I think Dadisa was awake when Jagya was telling Gauri off for saying Anandi was doing drama. I feel that Dadisa understands that despite what all Jagya said, somewhere or another he still cares about Anandi. Like you said, I think Dadisa will show Jagya the difference between Anandi and Gauri, she is letting Jagya and Gauri stay not for either of them but for Anandi