Thanks for a really great pattern. We all had fun making it.

I used a 3mm hook for most of the bag, 2.5mm for the top band.

front

I worked as pattern but wanted to flatten the shape of top edge so I tacked a line across the front where I wanted the edge to be (see photo) then adjusted the lengths of the rows to follow that line by unpicking 2 stitches each end of r33 and then unpicking 1 or 2 stitches each side of other rows.

I worked the joining round as pattern except I had 141 stitches as I had unpicked 2 each side on r33 on front

back

I worked back to match adjusted front row lengths. I also worked rows back and forth carrying yarn at top edge instead of cutting yarn each row:

R9 C3 WS turned work to set up for working back and forth in turned rows to minimize cut ends
R10 C1 as pattern from RS

from now on use yarn colour of choice, carried along top edge, and work odd numbered rows from WS plain hdc as per pattern. Even rows details below.

R11 C2 WS plain as pattern using C2 carried from R8
R12 C3 RS dec, 9, (inc, 8), dec decreases at start of row are to compensate for working in turned rows and to smooth edge
R14 C2 RS dec, 3, inc, 3, then repeat (7, inc, 2) to last 2, dec
R16 C1 RS dec, 3, inc, 3, then repeat (8, inc, 2) to last 2, dec
R18 C3 RS dec, 10, then repeat (inc, 11) to last 2, dec
R20 C2 RS dec, 5, repeat (inc, 12) to last 2, dec
R22 C1 RS dec, 7, repeat (inc, 13) to last 2, dec
R24 C3 RS dec, 4, repeat (inc, 14) to last 2, dec
R26-R33 - short rows to match front

top

worked in spiral as pattern
r1: 28 on each wing, 15 in centre, skipped join so 142 total (cf pattern 140)
r2: sc 24, hdc 7, sc 9, hdc 7, sc 24 x 2 (142)
I worked 7 rounds of sc for top of bag

zip

12” zip - sew WS of zip to RS of lining; sew RS of zip to inner edge of bag a couple of rows from top edge