N.W.
When I have ear infections and my ear hurts, pressing on it seems to warm the ear and make it feel better.
Even though your daughter doesn't have an ear infection anymore, she may be afraid her ear MIGHT hurt when she lies down. As humans we tend to avoid things that caused us pain in the past, even when they no longer present a danger. Like if you ate a food that was spoiled and got nauseated, you may get nauseated again when you smell the same food at a different time.
I wouldn't worry about it too much. She'll eventually realize her ear does NOT hurt when she goes to sleep and will stop one day. Just give it some time.