So this dress uses Scrumptious 4 ply/sport superwash by Fyberspates (http://fyberspates.com/), you will also need a 4mm and a 3.5 mm crochet hooks. All terminology uses UK crochet names.
This is made for a 5 year old, I have noted the places where you will need to extend if making for an older child.
Abbreviations
trc - treble crochet
dc - double crochet
Using 4mm hook chain 106,
Switch to 3.5 mm hook
Working flat
Row 1: Chain 3, trc to 16, pm, trc to 36, pm, trc to 66, pm, trc to 80, pm trc to end and turn.
Row 2: Chain 1, dc into each stitch to end.
Row 3: Chain 3, trc to marker (two trc into marked stitch place marker in middle stitch of the 3 trc) repeat to end and turn.
Row 4: Chain 1, dc to end
Row 5-22: repeat rows 3-4
This makes the top part of the dress which will now be joined to form the armholes so for a larger child add more rows here.
Hold foundation chain at stitch 26 and 80 and lift, the material will naturally fold enough and form the torso part of the dress. Make sure the increases match in each corner and begin the joining row.
Row 23: Chain 1 dc into each stitch, at end slip stitch to join with stitch 1 from now on the dress is worked as a round.
Row 24: Chain 3, trc into each stitch to end join with a slip stitch.
Row 25: Chain 1, dc into each stitch to end join with a slip stitch
Row 26-29: Chain 3, trc into each stitch to end join with a slip stitch
Row 30-39: Chain 1, dc into each stitch to end join with a slip stitch (This makes the waist shaping)
Row 31: Chain 3 trc into next 10 stitches, (trc 3 into next stitch place marker in the middle of the three stitches trc next 10 stitches) repeat to end join with a slip stitch.
Row 32-35: Chain 3, trc into each stitch to end, join with a slip stitch.
Row 36: Chain 3, (trc to marker, three trc into marked stitch, place marker in the middle of the three stiches) repeat to end, join with a slip stitch.
Row 37-46: Chain 3, trc into each stitch to end, join with a slip stitch.
Row 47: Chain 3, (trc to marker, three trc into marked stitch, place marker in the middle of the three stiches) repeat to end, join with a slip stitch.
Row 48-57: Chain 3, trc into each stitch to end, join with a slip stitch.
Row 58: Chain 3, (trc to marker, three trc into marked stitch, place marker in the middle of the three stiches) repeat to end, join with a slip stitch.
Row 59-68: Chain 3, trc into each stitch to end, join with a slip stitch.
Row 69: Chain 3, (trc to marker, three trc into marked stitch, place marker in the middle of the three stiches) repeat to end, join with a slip stitch.
Row 70-76: Chain 3, trc into each stitch to end, join with a slip stitch.
(If making for a larger child repeat row 69-76 until the correct length is reached)
Row 77: Chain 4, trc in second stitch from hook, skip a stitch, chain 1, trc in next stitch, repeat to end, join with a slipped stitch.
Row 78: Into second stitch from hook 6trc, skip stitch, dc into next stitch, (skip stitch, 6trc into next stitch, skip stitch, dc into next stitch) repeat to end.
At armholes attach yarn at the join at the bottom of the armhole,
Row 1: Chain 4, trc into second stitch from hook, (skip stitch, chain 1, trc into next stitch) repeat to end, join with a slip stitch.
Row 2: 6trc in second stitch from hook, skip a stitch, 1 dc in next stitch, (skip a stitch, 6trc in next stitch, skip a stitch, 1 dc in next stitch) repeat to end join with a slip stitch.
Repeat edging on second armhole.
To add buttons at the back:
Weave in all ends and block.
Enjoy!
Felicity