The Ex
Iris scrolled through social media and the internet. Harriet had millions of followers by a single post. She was a businesswoman in the shop that she had with her stepmother. That is why Harriet had a lot of admirers. A lot also DM her on her account but she never entertains any of them. She's busy with her work as she's not that aware of the number of people following her social media.
This is why Harriet got a stalker. Iris was accurate that the stalker was from a rich family. Driving around the porch, following them on their trip, not to mention spending time sending flowers every holiday even if it's not a holiday. Harriet never receives it since Astera Security would block it and would thoroughly check it including the letters.
One time, a simple note from an unknown stalker tells everything. Kane was there when the first letter came to Harriet.