Jill Francksen

Jill Francksen (sometimes spelled Franksen) contributed to Swift Annual 5 (1958) and 7 (1960) plus Robin Annual 9 (1961). I've not been able to find out anything about Francksen beyond a decade's worth of illustrated books. There was a J. H. Francksen who lived in Harrow Road, E.10 in 1939-57, but whether that's Jill is impossible to tell.

Illustrated Books
How to Survive Matrimony by Herald Froy. London, Frederick Muller, 1958.
Manual of Modern Manners. A practical up-to-date guide for all occasions by Judith Listowel. London, Odhams Press, 1959.
A Robin Story Book, ed. Marcus Morris; illus. with Sabine Schweizer. London, Hulton Press, 1959.
Tubby the Odd-Job Engine by Eileen Gibb. London, Hulton Press, 1959.
Can This Be Love? by Herald Froy. London, Frederick Muller, 1960.
The Modern Hostess. Entertaining with ease and economy on all occasions by Judith Listowel. London, Odhams Press, 1961.
Maybe You're Just Inferior. Head-shrinking for fun and profit by Herald Froy. London, Frederick Muller, 1961.
O Mistress Mine; or, How to Go Roaming by Herald Froy. London, Arthur Barker, 1962.
Every Girl is Entitled to a Husband by Nina Farewell. London, Arthur Barker, 1963.
366 Goodnight Stories, illus. with others. Feltham, Paul Hamlyn, 1963; New York, Golden Pleasure Books, 1963.
Tooters, Tweeters, Strings & Beaters. An instrument book for all young readers by Joan Fisher; illus. with Art Seiden. London, Odhams Books, 1965.
Toiz and Gaems (indorz) by R. P. A. Edwards & Vivian Gibbon. London, Burke Books, 1966.
Plaeing Outdorz by R. P. A. Edwards & Vivian Gibbon. London, Burke Books, 1967.
What Things Are Made Of by R. P. A. Edwards & Vivian Gibbon. London, Burke Books, 1968.

(* Illustration from Swift Annual 5, © Look and Learn Magazine Ltd.)