A poster in another forum asked about a separate thread for Helena, daughter of Queen Victoria, also known as Princess Christian of Schleswig-Holstein, or by her nickname, Lenchen. (I did a search and could not find a separate thread for Helena. If one does exist and I searched incorrectly, please forgive!!)
Princess Helena was born on May 25, 1846, the fifth child and third daughter of Queen Victoria and Prince Albert. She was close to her brother, Alfred, and known to be athletic and interested in machinery as a child. She was very shy, and very much affected by her father's death in 1861. Helena married Prince Christian of Schleswig-Holstein, a minor German prince fifteen years older than herself, in 1866. Though the marriage was somewhat arranged by Queen Victoria in order to keep Helena in Britain (and near her mother), Helena and Christian grew quite fond of each other. The couple resided chiefly at Frogmore House and Cumberland Lodge. The two had six children, though only four survived infancy. With the exception of her sister Louise, who had no children, Helena is the only one of Queen Victoria's children not to be an ancestor of one or more current European monarchs or consorts. Helena's only grandchild, Valerie, was an illegitmate daughter of her son Albert; Valerie died childless. Princess Helena was also a patron of several charities. She died on June 9, 1923.
Helena has a single biography written about her, Helena: Princess Reclaimed by Seweryn Chomet. It's quite short and somewhat strangely written (I thought it read like a very rough draft of a dissertation), it does provide some lesser-known facts about Helena. For instance, she had a flirtation/first love with a Royal Librarian, Carl Ruland, which may have resulted in Ruland's departure from staff. Marie Louise, one of Helena's daughters, described her mother as having a "wonderful head for business." Helena also was apparently a talented writer and artist, though her gifts were not as developed as those of her sisters Vicky and Louise. She is, perhaps sadly, one of the least known children of Queen Victoria, possibly due to her lack of living descendents, her shyness, and her marriage to a less prominent prince. Perhaps one day she will be rediscovered by historians.