Heather, I am sure it was a sign from her. I am so sorry for your loss.
When we lost Bruno very suddenly I wished for a sign too. I did some washing the day after he died - nothing of his, just our usual stuff, and tumble dried the load. In the fluff compartment of our drier right after the load had finished, right at the front where I could not fail to see it, was a magnificent whisker of his. I have never found one in the fluff basket before or since. I love to collect discarded whiskers, so I am sure it was from him xx
You are in my thoughts and prayers. Rest peacefully, dear Tabby