Hey everyone…thanks for the tips.
I thinkg I’ll wait until Sunday morning passes before implementing your suggestions - or my neighbors might string me up 
Maybe if you stay home and practice on Sunday mornings, you’ll encourage your neighbors to go to church? Music is good for the soul!
““This is where a bit of tonguing can be a help. Instead of starting the note with a sort of huff of air, silently say the letter “T” to release a little burst of air to get the note started. You don’t want it to sound like a sharply articulated, staccato note…””
This seems to be helping a lot…and the squinting, too!
I have 2nd-octave problems too. I adore the sound of my Walton whistle, but I hate the second octave (I’ve read that they do tend to be difficult). If I don’t overblow as if overblowing is going out of style, it’s flat. Unfortunately, blasting the birds out of the sky isn’t my idea of a good time either, esp. since I’m not that great on the second octave yet. I’ve tried changing the shape of my airflow but it doesn’t seem to make a difference (however, I’m a string and handbell player, not a wind player of any sort, so maybe there is something about embouchures and such that I don’t know). I just try to avoid songs that go above about G in the second octave so nobody calls the police when I practice. I’ll try the tongueing, though.
The Sweetone I have that was my mom’s is better, but I don’t really like the sound of it. My Clarke (original) does a great job on the second octave (so effortless compared to the Walton) but it’s a C, and I prefer the smaller air requirements of the other two anyway, and I also hate that I can’t use OxxOOOO fingering for the Bflat [Cnat] (though I do like the Clarke sound as well).
(Is Jerry’s Mellow Dog better on 2nd octave than the untweaked Waltons? I just really like the Walton sound and would rather stick with that brand… I’d be sad to give up my current whistle at all, but if I had to…)
Are you sure that what you think is the first octave isn’t actually the second? It’s not unheard of for a beginner to find the second second octave first and then have trouble getting higher.
I like The Sailor’s Wife - builds up to climbing the octaves, goes one note into the third.
Um… yes. As stated, I do know about music, I am just not very experienced in wind instruments (my brief stint of self-taught recorder when I was 8 is the most I had prior to picking up a whistle). And since I can force it into the 3rd-octave D (painfully), then either I am indeed starting in the first octave, or I’m some sort of prodigy who’s managed the fourth.