What a great photo of the bride and her tiara! Thank you The Royal Watcher!
I think that both Sam (The Beau Monde) and The Royal Watcher are correct and that Lady Charlotte was wearing a tiara from her family.
I have only one photo of a Countess of Lindsay wearing a tiara and, despite the fact that it is a very low quality photo, I think the tiara is the one worn by the bride.
What does everyone think?