Who is Beattie in the novel, The Kitchen House?

Beattie is a twin, one of Mama Mae’s youngest children. Beattie and Lavinia grow up together at Tall Oaks. Beattie is a kind, gentle young girl who is always good to Lavinia. However, after Lavinia is married to Marshall, Beattie finds herself in a difficult position when Marshall begins forcing her to have an affair with him. At first, Lavinia is angry with Beattie and treats her badly; but, after awhile she realizes the truth and Beattie again becomes her friend.