Question: What language did the author of the Moomin series speak even though she was Finnish?

Context articles: Tove Jansson
Moomin (1969 TV series)
Little My
Moomin (1990 TV series)
Moominvalley in November
The Exploits of Moominpappa
Snufkin
Tales from Moominvalley
The Dangerous Journey
List of Moomin (1990) episodes

Tove Marika Jansson (] ; 9 August 1914 – 27 June 2001) was a Swedish-speaking Finnish novelist, painter, illustrator and comic strip author.
 Brought up by artistic parents, Jansson studied art from 1930 to 1938 in Stockholm, Helsinki and then Paris.
 Her first solo art exhibition was in 1943.
 At the same time, she was writing short stories and articles for publication, as well as creating the graphics for book covers and other purposes.
 She continued to work as an artist for the rest of her life, alongside her writing.
Moomin (ムーミン , Mūmin ) is a Japanese anime television series which was broadcast on Fuji Television between 1969 and 1970.
 The series is loosely based on the Moomin books by the Finnish author Tove Jansson.
 A sequel series entitled "Shin Muumin" (New Moomin) was later released in 1972.
 However, Jansson never approved of these series, due to dramatic changes with the plots, overall atmosphere, and character personalities.
Little My (original Swedish: "Lilla My" (literally: "little mu") is a character in the Moomin series of books by Tove Jansson.
 The character first appeared in the fourth book, The Exploits of Moominpappa (1950).
 She is a small, determined and fiercely independent Mymble.
 Little My is brash, aggressive, mischievous and disrespectful, but can also be a good friend when she wants to.
 She is the Mymble's daughter's younger sister.
 She was eventually adopted by the Moomin family.
Moomin (Japanese: 楽しいムーミン一家 , Hepburn: Tanoshii Mūmin Ikka , "Delightful Moomin Family") is a Japanese-Finnish-Dutch anime television series produced by Telecable Benelux B.V..
 Based on the "Moomin" novels and comic strips by the Finnish illustrator and author Tove Jansson and her brother Lars Jansson, it was the third anime adaptation of the property and the first to receive distribution in other countries worldwide.
 "Moomin" first aired on TV Tokyo from April 12, 1990 to October 3, 1991.
 The series has also been dubbed English and aired on CBBC in United Kingdom during the same year.
Moominvalley in November (Swedish: "Sent i november", 'Late in November'; Finnish: "Muumilaakson marraskuu") is the ninth and final book in the Moomin series by Finnish author Tove Jansson, and was first published in both her native Swedish and English in 1971.
 Set contemporaneously with her previous novel "Moominpappa at Sea" (1965), it is the only installment in the series where the titular Moomin family are actually absent.
 Instead it focuses on a set of other characters, including Snufkin, who come to live at Moominhouse during the onset of winter whilst its inhabitants are away, and the various interactions which they have with each other.
The Exploits of Moominpappa, first published in 1950 and then considerably revised in 1968 under the title Moominpappa's Memoirs, is the fourth book in the Moomin series by Tove Jansson.
 The story found in this book is mentioned in the previous Moomin books, as Moominpappa writes his memoirs in those stories.
 Unlike "Comet in Moominland" and "Finn Family Moomintroll", both versions of the novel were translated into English.
 "Exploits of Moominpappa" forms the basis of episodes 59, 63 and 68 in the 1990 TV series.
Snufkin (original Swedish: Snusmumrik[en]" or Mumrik[en]", Finnish: Nuuskamuikkunen or Muikkunen) is a character in the Moomin series of books authored by Swedish-speaking Finn Tove Jansson, appearing in six of the nine books.
 He is the best friend of the series' protagonist, Moomintroll, and lives a nomadic lifestyle, only staying in Moominvalley in the spring and summer, but leaving for warmer climates down south every winter.
 He is the son of the elder Mymble and the Joxter, and is half-brother to the Mymble's daughter and Little My.
Tales from Moominvalley (Swedish: "Det osynliga barnet och andra berättelser", literally "The Invisible Child and other stories") is the sixth book in the Moomin series by Finnish author Tove Jansson.
 Unlike all the other books, which were novels, it is a collection of short stories, the longest book in the series.
 It was first published in 1962 (second edition 1998).
 The book forms the basis of episodes 9, 10, 13, 24, and 36 of the 1990 series.
The Dangerous Journey (Orig.
 Swedish "Den farliga resan") is a children's picture book in the Moomin series by Tove Jansson.
 It was published in 1977.
 It follows the nightmarish adventures of Susanna, the Hemulen, Sniff, Sorry-Ooo and Thingummy & Bob through Moomin Valley.
"Moomin" (Japanese: 楽しいムーミン一家 , Hepburn: Tanoshii Mūmin Ikka ) is an anime television series produced by Telecable Benelux B.V., that is based on the Moomin novels and comic strips by the Finnish illustrator and author Tove Jansson and her brother Lars Jansson.
 The anime series premiered on TV Tokyo on April 12, 1990 and ended on October 3, 1991 with 78 episodes being made.
 Because of its huge success in Japan, the sequel series, entitled Delightful Moomin Family: Adventure Diary (楽しいムーミン一家 冒険日記 , Tanoshii Mūmin Ikka: Bōken Nikki ) was made and first aired from October 10, 1991 to March 26, 1992, lasting 26 episodes.
 The sequel series has only been aired in certain countries outside Japan, where it is featured as the second season of "Moomin", combining two series resulting in 104 episodes in total.
 Unlike the original series, the sequel series doesn't have any episodes based on Tove Jansson's books.
 However, part of its episodes are based on Lars Jansson's comic strips.