I am a sub-contractor for a retail store. The home owner purchased plantation shutters through the designer and my company manufactured them. I do not have a contract with the homeowner. My business was done solely with the designer/retail store. After two months of completing the job, the designer did not pay me. I filed a Notice of Intent and sent it to both homeowner and designer. The homeowner contact me and accused me of fraud because she said she had paid for the product via the designer. I explained to her that I had to send the letter to both her as the homeowner and the designer. She then threaten to sue me. Can she do that?