My wife was recently given a 400+ year old painting by a now deceased aunt. I cannot find a signature. Can anyone help us identify the painting and artist?

Sorry, I can't stand on my head and look sideways at my computer screen. If you really believe it is 400 years old, go to a qualified art historian and have it assessed. A qualified art historian can see it, feel it and look at the back and front. Probaby diagnose the paint to decide when it was painted.