Polite, warm, and then the gift card goes in a drawer.
A gift card says you wanted to get it right and weren't sure how. It's practical, and she'll use it. But nobody remembers opening one. There's nothing to hold, nothing to look at in a year, and nothing that tells her you were thinking about her in particular.
This is the opposite. It's a gift she has to open: a bear, a glass dome, a real rose, a little key. Then, behind the rose, a necklace you chose for her. The opening is half of the gift, and it's the part she'll remember.
You choose the necklace. We put it inside the box and send it in one parcel, so you hand it over exactly as it arrives.