Well, Helena was Lenchen, Beatrice was Bee, Louise (Duchess of Argylle) was Loosy. Some of hte grandchildren had pet names too, such as Willy for the German Kaiser, Moretta for his sister Victoria, Mossy for Margaret of Prussia and I think Sossi for Sophie Princess of Prussia.
Arthurs 2 daughters were called Daisy and Patsy....
Helena's children were Christian (Christle) Albert (Abby) Helena Victoria (THora) and I think Marie Louise was known as Louie.
The Waleses were Albert Victor (Eddy) George V (Georgie) Louise (Loo), Victoria (Toria) and I dont know if Maud had any nickname.
Re the children of Louise Duchess of Fife, I dont know of them being called by abbrevations or pet names...but they are not well known.
Alice had 7 children, most of whom had a pet name. Ernest was Urn, Friedrich Frittie, Elisabeth - Ella, Alix - Alicky, and Marie was May....
Alfred's daughters were Marie (Missy), Victoria Melita (Ducky) Alexandra (Sandra) and Beatrice (Baby Bee).
those are all I can remember for now....