1. Anandi will always resist her feelings for Shiv because she thinks that she still and will always love Jagya.Moreover she will resist her feeling because of her responsibilities towards the Singh family.Though sumitra has always loved her as a daughter but still there is always a difference between sharing such feeling with a mother and a MIL.As a result if there will be no one to make anandi understand her feelings she will dig those feelings deep into her heart forever.
2.There is also a resistance from Shiv's side.First that whether it will be right to see a married girl from that pov or not.Moreover even if he starts liking her,there will be doubt in his mind that whether his royal family will accept a girl from a village or not.
Moreover as dadisa said earlier, in order to make anandi go closer to shiv it is important to interact with someone who is very close to shiv.Obviously bheem singh can give only info about what Shiv likes in food or what is his daily schedule.Not more that that! Whereas its Ashi only who will make Shiv realize that he is falling for Anandi and bring them closer by giving anandi a makeover.So in my view ashi is no gauri- I mean she is not at all a third angle in the Shivan story.And already one Gauri is enough to test the patience of audiences😆