Who is Esther 'Pookie' Grimes from The Easter Parade: A Novel and what is their importance?

Esther 'Pookie' Grimes is Emily and Sarah's mother. Pookie divorces her husband on a whim, determined to become rich and famous on her own if her husband cannot take her there. However, Pookie eventually comes to realize that life on her own is not all she thought it would be. Pookie asks her husband to come back, but he refuses out of fear of another broken heart. This leads to depression for Pookie.