Domino Lady is not a property of Moonstone Publishing which has released a lot of product on this character including novels and comics and more! FYI
Richard aka Mr_Goldenage
Did you mean "now" instead of "not"?
According to pdsh she is in the public-domain, but maybe it's the 1930s stories that are in the public domain, and the character itself isn't. However, not only Moonstone, Airship 27 has also been publishing stuff with the character for years, at the same time. Those being 2 different companies, could it be that the character really is public-domain.
I couldn't find the pulp magazine the 1930s stories appeared in uploaded anywhere however. There are recent compilations of them for sale though (and new stories).