Ok everyone treats MC like she was Feng Qingge, but she’s only inherited the the body from its previous owner and is a different person inside.
“Her” memories of the grandfather is not her own. That’s not MC’s grandfather, but the original owner’s grandfather. I don’t see why she’s emotionally attached to the grandfather when she didn’t feel the same with her body’s original lover.
And the original owner is dead. Even if the grandpa saw through the veil, the person he recognized as his granddaughter is still a different person on the inside.