That is lovely and how apt that she should be called Angel.
I have had experience of a mourning dog and its so sad because they can't tell you how they are feeling. When our old black Lab, George, passed away our girl, Millie (yellow Lab) pined so much that she stopped eating. The vet said either he could put her on antidepressants or - better - we could get her a new companion. And that's why we got our Labradoodle Archie. It was amazing, the evening he came to live with us she started eating again and they absolutely adore each other.