I used Sweet Ivy by Drops for the 12-18 months’ sizing cast on Dina by Sandnes

with 4mm double pointed needles make 85 rows of a 3st I-cord.

With your 3mm needle pick up 85 stitches along the I-cord.

Remember to make the Knitside edges with k1, s1pw wyif, k1, p1……. purlside edges with s1 purlwise wyf, k1, s1 purlwise wyf,

With your 3.5mm needle knit the first row while placing markers after the first four stitches and in front of the last four stitches of the row to remind yourself to make the cord placket edges. Also place markers for the raglan increases.

Row 1: k1, s1pw wyif, k1, p1, pm, k13, pm, k 2, pm, k6, pm, k2, pm, k31, pm, k2, pm, k6, pm, k2, pm, k13, p1, pm, k1, s1pw wyif, k1.

Row 2: s1 purlwise wyf, k1, s1 purlwise wyf, k1, sm, purl across to last marker, sm, k1, s1 purlwise wyf, k1, s1 purlwise wyf

Row 3: k1, s1pw wyif, k1, p1, mm, k13, m1l, mm, k 2, mm, m1r, 2kfb, k1, 2kfb, k1, m1l, mm, k2, mm, k1r, k31, k1l, mm, k2, mm, k1r, 2kfb, k1, 2kfb, k1, m1l, , mm, k2, mm, k13, mm, p1, k1, s1pw wyif, k1. (101 sts)

Row 4: s1 purlwise wyf, k1, s1 purlwise wyf, k1, sm, purl across to last marker, sm, k1, s1 purlwise wyf, k1, s1 purlwise wyf

Row 5: k1, s1pw wyif, k1, p1, mm, k to m, m1l, mm, k 2, mm, m1r, k to m, m1l, mm, k2, mm, k1r, k to m, k1l, mm, k2, mm, k1r, k to m, m1l, mm, k2, mm, k to m, mm, p1, k1, s1pw wyif, k1 (109 sts)

Repeat rows 4 and 5 13 more times (202 sts)

Continue without further increases until the piece measures 12cm.

Work the next round as follows: Work the first 31 stitches, place the next 40 stitches on a thread for the sleeve. Cast on 8 stitches (in side under sleeve), work 61 stitches (front piece), place the next 40 stitches on a thread for the sleeve, cast on 8 stitches (in side under sleeve), work the last 30 stitches. (138 sts on body)

The body and sleeves are finished separately.

Body:

pm in the middle of the cast on sts under the sleeves for the BOR and the half way round.

Knit 26 rounds
On the 11th and 22nd rounds m1r and m1l on either side of the markers the same way you made the raglan increases. (146 sts)

Peplum:

How to make the balanced 1 st increase: Insert needle purl wise into next stitch.
Lift the stitch off the left needle and drape it over top of that left needle so it lies flat.
Now knit the right hand bar of that loop and pull it off of the left needle then go back and insert your needle knitwise into the left bar of that loop And knit that side as well and pulling it off the needle.

Rnd 1: k1, make a 1st increase in next st, repeat adding 73 new sts (219 sts)
Rnd 2 to 22: knit
Rnd23: purl
Rnd 24: k1, yo, k2tog repeat
Rnd 25: purl
Rnd 26: 2st bind off cast 2 st on left needle, k1, k2tog through back loops, slip the 2 st on the right needle onto the left needle , k1, k2tog tbl, slip the 2 st on the right needle onto the left needle, repeat

2 st I/cord bind off: https://youtu.be/Mu4I8VoFdLw?si=9u6cOyBr9NcJm0zk

Purl 1 round
K2tog, yo, k2tog, yo …..
Purl
2st I-Cord cast on two sts, k1 tfl, k2tog tbl, put the 2 sts back on the left needle, repeat-.

Sleeve:

Put the 40 sleeve sts on a needle and pick up 8loops of yarn through the 8 sts under the sleeve that were cast on for the body. (48 sts)

pm for BOR after the fourth under arm sts

Rnds 1-8: knit all stitches

Rnd 9: k1 k2tog, knit up to 3 sts befor BOR marker, k 2 tog, k1 (46 sts)

Repeat rnds1-9 four more times (38 sts).

Knit all further rounds until arm measures 18cm

Bind off with a 2 stitch I-cord bind off.

https://youtu.be/r1gAvmhnHF0?si=ijp3_5BbpvAz8lCp