Here's a look at Venla, which is currently (2017) Finland's #4 most popular girls name. This #1 pick is a form of the boy's name Wendel, meaning "vandal." An older form is Vendla, and an alternate Swedish form is Vendela. Wendelin is the ancient Germanic male form, Vendelin the Czech form. Wendela and Wendelina pop up for girls from time to time, giving the option for Wendy as a nickname. Venla is used in Sweden, Norway and Denmark as well, just not as much. It has not been used in the U.S.
The first novel written in Finnish, Seven Brothers, features a character named Venla of Männistö. This may have brought attention to the name when it was published in 1870, bringing it from zero to at least five births in 1920. The Venla relay is the women's version of the more commonly known Jukola relay, an orienteering relay race that started in 1949 because of the Seven Brothers novel.
Since 1982 the Venla has been a Finnish television award. Venla Hovi is a Finnish ice hockey player, and Venla Niemi is a Finnish orienteering competitor,