[Kate’s] been so happy and excited for the wedding, and that hasn’t dissipated, but it has finally hit her that her mother won’t be there for this. Matilda mentions that if she had a daughter “this is exactly the kind of dress [she] would want for her.” With her standing there in that wedding dress—which I don’t love, but might feel differently about when she’s all done up with hair and make-up and Castle in a tux—she subtly touches the spot where her mothers ring sat all those years, where she was shot in search for her mother’s killer, and it hits her that her mother isn’t standing behind her. And it gives her pause.
Kate’s character development is in full force with the wedding prep, as seen in this screencap of a screencap:
From 4×01 to 6×14, Kate doesn’t need anymore time!
More here! Castle 6.14 Review “Dressed to Kill”.