Sarah Covington Kerr was born at Washington on April 3rd, 1876, having a romantic legend connectted with her name, also derived from the family of her paternal grandmother. (from Chamberlaine Geneological Notes)

She was just under two years old when her father died. While growing up, she was also called 'Sarita' by her family which was later just shortened to just 'Rita.'

From the personal journals of HMK:

Washington, D.C. Nov. 1880
Sarah, the baby, & pet of the household, was born in this city, on Mamma's birthday, April 3rd, 1876. She is in my eyes, a perfect little beauty & her nature is as lovely as her face. She has a delicate white skin, & in her forehead, the blue veins can be distinctly traced. Her eyes are deepest, darkest blue-indeed, sometimes at night they look jet black,-and they shine like stars! Her features are perfect, small & regular; even her little ears are like pink shells,& in her soft round chin there is the dearest little dimple, as well as several smaller ones around the mobile mouth. She rarely has any color in her cheeks, but her lips are always crimson. Her hair is pure gold, & falls behind in soft curls to her shoulders; in front it is cut short, the light "wavy" bangs being in marked contrast to her eyebrows & lashes which are dark. In frame she is very slender and she has never been robust, though far from a sickly child. She is not at all spoiled, & I only hope that she will be as lovely in every way when she is a woman, as she is now.

December 14th, 1903
Rita too is married;-to Maitland Riely, a Virginian.-They now live in New York and have a dear little two year old daughter Corinne Reily;-and are expecting another in February. -They made a "runaway match" and are very poor; I am not sure how happy they are, but know they love each other, so hope all things.