Need help shaping a sleeve cap

I am knitting a lacy jacket for a 6 month old. The lace pattern stitch is a traveling leaf (multiple of 12 sts). K1, YO, K3, K2 tog, K1, sl 1, K1, PSSO, K3, YO. I am now at the shape cap and I need help. There are 49 stitches on the needle. The instructions say to keep pattern correct while binding off 3 stitches at beg of next 2 rows, then dec one st at each end of next row and then on every other row until 15 st remain, then bind off the 15 st. I am not sure how to keep pattern correct while decreasing stitches. Help…
Thank you.

After the BO and a few decs, it may be easier to keep the beginning and end sts in stockinette st. Mark where your second pattern repeat begins and do the sts before that in st st. You can also graph it out with symbols to denote knits, decs and YOs, then when you BO 3, you’ll be starting on the 5th st (because the 4th st was done in the last bound off stitch). Then you lose a stitch each side every RS row, so you just start one more stitch over; the end of the row is eaiser, just knit until you run out of stitches. By now though you should be able to read the pattern in your stitches and continue them on even losing the ones at the edges.

And just for good measure, before you start all this decreasing, for heaven’s sake (and yours, too), put in a lifeline. That way if something goes awry, you can at least get back to where you know all is right!

The YOs are balanced on each half of the repeat by the k2tog or the s1k1psso. So if you’re going to decrease and lose a YO, you’ll need to eliminate the k2tog on that side or the sl1k1psso at the other side. One way to do this is to replace half the pattern stitch at the edges with stockinette stitch. Instead of
K1, YO, K3, K2 tog, [U]K1, sl 1, K1, PSSO, K3, YO[/U]…[U]K1, YO, K3, K2 tog, K1[/U], sl 1, K1, PSSO, K3, YO k1.
You would have
K1, K2 , [U]K1, sl 1, K1, PSSO, K3, YO[/U[U]]…K1, YO, K3, K2 tog, K1,[/U] k2, k1
The 3 sts for the underarm have been decreased and the pattern repeat decreases have been replaced with stockinette. (I’ve added the final k1 in assuming it’s the 49th stitch with 4 pattern repeats.)
When you’ve used up the stockinette sts in decreases, do the same kind of decrease again to convert some of the pattern repeat to stockinette.

Thank you so much. I am going to try it now.