I ended up ripping out the entire yellow blanket and restarting it. But I made the central part narrower – only three instead of four repeats. I slimmed it down based on yarn consumption estimates, and because I decided to trim it out with an edging rather than leaving it plain. I haven’t done much thinking about the edging’s corners. I’m winging it when I get to each. Photography is hard right now, so I present the traditional String photo of something wadded up into a mega-snood on a circ:
One of the things I find most comforting about knitting is that mistakes are not forever. Unlike say woodworking in which once your lumber is cut, it’s cut, with some minor exceptions, it’s always possible to rip out knitting and begin again. Since I’m one of the process rather than end-product oriented knitters, and deplore deadlines of any kind outside of my professional life, having to rip back isn’t a major burden. Of course, I do sometimes get annoyed at wasted effort and sometimes am frustrated enough to consign a project to Chest of Knitting Horrors(tm) limbo, most of the time it’s just grab the end and rewind.
Work schedule willing, I should have this blanket finished by next week. That will be Baby Gift #2 done, and I’ll be on to #3.
String-Or-Nothing 
It is very comforting to me that you, who are so far above me in knitting smarts,applied math (to knitting) and a lace wizard, make mistakes. I don’t feel so bad, now.
BTW like the zig-zag edging to the baby blanket– a nice echo of the lace pattern.
–Kathryn