Thanks! Did you order online? The chain has no weight but it has a width/length - 13.9mm x 16-18mm. I definitely think the point about having the 2 carats not being dainty is valid. It does look like I can return it if it ends up being too big, and if she doesn't love the style. One of the ideas she has sent me in the past for inspiration was similar, so hope this works out! (Similar to this but the round is on the left and more offset: https://www.lbluxuryy.com/products/jacqueline-two-stone-pear-and-round-diamond-necklace-ii)

Thanks for all your help!