This pattern is called Sweethearts in Easy Knits for Kids. This name does not appear in the leaflets.

In Easy Knits for Kids the pattern is on Page 26 and is illustrated on page 27.

Measurements
To fit chest
41, 46, 51 cm (16, 18, 20 in)
Length from back neck
28.5, 30, 31 cm (11¼, 11¾, 12¼ in)
Sleeve seam
15, 15, 18.5 cm (6, 6, 7¼ in)

Each source has a different set of recommended yarns. The following are from the Loweth pamphlet.

Materials
LOWETH DOUBLE KNITTING
Knit and Crochet DK
5, 6, 6 20 grm balls
Olympus DK
2, 2, 2 100 grm balls
Poppet Baby DK
3, 3, 3 40 grm balls
Contrast: 1, 1, 1 ball
3 buttons
stitch holders.