Direct Swap - Nicole from Netherlands

At the end of the summer Nicole was offering arty alphabet cards to swap through the form. I was happy to hear the "S" was available and we agreed to a swap. She was looking for stamps showing cats and/or dogs. I was lucky to still have some of these stamps promoting pet adoption. My card arrived shortly after with another great Europa stamp. So far I have never heard from Nicole to see if my card arrived. I've sent a few messages and they have not been read nor responded to. I can assume she has or she would have been in touch. How long would you wait before you "close the file" so to speak?