I love this pattern and can see why so many clever ravellers have made these sweet booties.

I used a slightly lighter weight yarn (DK) for the sole and found that the 12 month size pattern with 3.5mm hook produced a 3.75” (9.5cm) long bootie in a nice firm fabric (blue ones). Floss will be 6 months old though so I made the pink ones slightly larger - 4.25” - I added 2 chain to foundation to lengthen sides & added 1 row to tongue before last row & 1 row to sides (to finish with 24 stitches); otherwise, the pink ones have the same mods as detailed below.

The mods I’ve included below have 2 purposes - adjusting for lighter weight yarn and keeping everything slavishly symmetrical.
to keep seam neat & centred on heel:
on R1, sc2 in 2nd chain & ss to 1st sc (rather than sc in 2nd chain & ss into ch1) to keep stitch count to 26;
on R2-R7, at start of round, replace ch2 (which counts) with ch1 (that doesn’t count) and work 1st sc into stitch immediately below; at end of round, ss to 1st sc (rather than to ch2); pull the ss tight to make it less evident;
to widen heel a little for chubby baby feet: work all sc’s not ss’s along straight (as in newborn version);
to keep toe symmetrical - work over even number of stitches (as total stitches is 52) & work dc2tog either side of centre front rather than dc3tog

Pattern with my mods included:
soles in white on 3.5mm hook:
foundation: ch 13 (or magic loop + ch12);
R1: sc2 in 2nd ch, sc in next 10 ch, sc3 in next chain, rotate work and sc in other side of next 10 ch, sc in last (makes 3sc), ss to 1st sc; (26)
R2: ch 1 (does not count), sc in same stitch, 2sc in next sc, sc 10, 2sc in next 3, sc 10, sc 2 in last sc, skip ss & ch1, sc again in 1st stitch (this puts seam in centre); ss to first stitch of this round; pull tight; (32)
R3: ch 1 (does not count), sc in same stitch, 2sc in next 2 sc, sc 8, hdc 2, 2hdc, 2hdc, sc 2, 2hdc, 2hdc, hdc 2, sc 8, 2sc, 2sc, sc in last sc, skip ss & ch1, ss join to 1st sc, pull tight; (40)
R4: ch 1 (does not count), sc in same stitch, 2sc in next 3 sc, sc 12, 2sc in next 3 sc, sc 2, 2sc in next 3 sc, sc 12, 2sc in next 3 sc, sc in last sc, skip ss & ch1, ss join to 1st sc, pull tight; (52) (3.75” long)
sole sides in white on 3.0mm hook:
R5: (using 3mm hook for R5-R7), ch1, sc in very back loop of same stitch and of each sc around, skip ss & ch1, ss to 1st stitch; (52)
R6: ch1, sc in same stitch and around under standard both loops, skip ss & ch1, ss to 1st stitch (52);
R7: ch1, sc in same stitch and around in back loop only, skip ss & ch1, ss to 1st stitch (52);
(alternative finish for R7: cut yarn and pull through last stitch without YO; work invisible join into 2nd sc of R7; (for even more OCD approach, replace 1st sc of round with ss so that it tucks under the false stitch created by the invisible join))
colour stripe in colour on 3.0mm hook
no mods - ss (surface chain) around from back working in space at base of R7 stitches above horizontal line formed by front loops left unworked on R6;
toe in white on 2.5mm hook
preparation: find 2 centre front stitches, count back additional 7 sts along either side and place markers (16) (check there are 18 stitches remaining either side around to back);
2.5mm hook is just to make picking up stitches easier; make sure to work dc2tog firmly to avoid gaps;
R1: working standing dc in loop behind the back loop of marked stitch right side of front, dc, (dc2tog) 6 times, dc, dc, turn (10)
R2: ch2 (counts), working through both loops dc10tog, fasten off;
weave in all ends (yes susan, this means you!)
tongue in colour on 2.5mm & 3.0mm hooks
(odd# rows are right side, even# are wrong side)
R1: with 2.5mm hook attach yarn, ch1 then sc 9 sts across the toe edge (i.e. 4 either side of dc10tog), ch1, turn (9sts)
(note - I didn’t count ch1 so instead picked up 9 ‘real’ sc’s)
switching to 3.0mm hook & working through both loops
R2: 2sc in 1st sc, sc8, ch1, turn (10)
R3: 2sc in 1st sc sc, sc9, ch1, turn (11)
R4: sc in each sc across, ch1, turn (11)
R5: sc in each sc across, ch1, turn (11)
R6: 2sc in 1st sc, sc10, ch1, turn (12)
R7: 2sc in 1st sc, sc11, ch1, turn (13)
R8: sc in each sc across, no ch, turn (13)
R9: skip 1st sc, sc2, hdc2, dc3, hdc2, sc2, ss; fasten off, weave in ends.
uppers in colour on 2.5mm & 3.0mm hooks
(odd# rows are right side, even# are wrong side)
(count stitch created by invisible join on R7 as 1st stitch of round of that round (not last);
R1: (all stitches are worked in loop behind back loop) attach yarn in front of toe & with 2.5mm hook, work sc through loop already worked by 2nd last dc in 1st row of toe (working around that loop into space between 2 toe dc’s), sc similarly through loop at base of last dc of toe R1, sc in each stitch around to other side, sc in base of last dc and 2nd last dc of toe; no ch; turn (40)
switch to 3.0mm hook and working through both loops
R2: (no ch) sc2tog, sc to centre back, sc2tog, sc to last 2sts, sc2tog, turn(37)
R3: (no ch) sc2tog, sc to centre back, sc2tog, sc to last 2sts, sc2tog, turn(34)
R4: (no ch) sc2tog, sc to last 2sts, sc2tog, turn(32)
R5: (no ch) sc2tog, sc to last 2sts, sc2tog, turn(30)
R6: (no ch) sc2tog, sc to last 2sts, sc2tog, turn(28)
R7: (no ch) sc2tog, sc to last 2sts, sc2tog, turn(26)
R8: (no ch) sc2tog, sc to last 2sts, sc2tog, turn(24)
R9: (no ch) sc2tog, sc to last 2sts, sc2tog, turn(22)
fasten off, weave in ends.
star circle in white on 3.0mm
9hdc in magic loop; finish with invisible join into 1st hdc to create 10 identical stitch tops around the outside.
I followed the tips for working the stars and attaching the logo from https://www.ravelry.com/projects/loopysue/crochet-baby-co... (happy with the lighter star from front so didn’t change).
laces in white on 2.5mm tightly!
ch150
I avoided having to use glue by unravelling the yarn strands at ends and dividing them roughly equally. Of the 5 strands I had, I wove in 2 strands, following the spine of the chain down and splitting the stitches as I went. Because it’s only 2 strands this is almost invisible. I cut the remaining 3 strands to give a frayed looking end that won’t unravel because the other half of its strands are woven in.
I found a great tutorial on how to tie neat, secure and symmetrical laces here https://www.youtube.com/watch?v=1RbaIo4VdbA (bonus - my own shoes don’t come undone any more!).

And here’s a tutorial for a cute box - http://www.gatheringbeauty.com/2015/02/simple-diy-gift-bo....