Thanks everyone!
I am so glad I joined this forum! Nice people! Who knew such creatures existed?
More specifically, thanks very much, caco.
You're right that "I smile and pretend I can't see" is the best of the options on its own terms. I am very tempted to put it back in... But whereas in Tinder Box, the amazing song of yours I commented on, you use the repetition of individual words to build up texture and mood, I haven't given myself much space to do that here. When I read the lyrics with the first "smile" line in, the second "smile" at the start of verse two seems accidental. (I have repetition of whole lines, but that's a different thing, of course.)
I think I will change "get" to "make". I am too addicted to rhyme. I need to wean myself off. This is a pitfall of loving musicals.
I know what you mean about the structure of the middle section. For all that I said I need to wean myself off rhyme, it'll have to be baby steps, because I want to keep the "know me / knows me / shows me" feminine rhyme here. But the section structure does seem odd. I think it's because there are only three of those short lines, which is musically counter-intuitive. Doable, but certainly counter-intuitive. Your solution sidesteps that as well as better connecting the friends, the mirror and the girl's state of mind. So it is very good. BUT IT ONLY RHYMES ON THE SECOND SYLLABLE OF A FEMININE RHYME!
(The rhyme-rage has returned. I will have a sit down.)
The reason I included the "But they don't know me" line, which throws the structure off, is that it felt too abrupt to go straight into "The mirror knows me" - it seemed apropos of nothing. But if I introduce the word "know" earlier, and try to make some word-repetition work for me in this section, that might do the trick. How about:
And my friends say that I could do better,
But they don't know me, know how little I'm worth.
They say make a plan,
Get a better man...
But the mirror knows me,
And the mirror shows me
I'm the luckiest girl on Earth.
The second line gets lengthened here, but whenever I sang the original line in my head, I had to drag out the second syllable of "little" to fill the bar, so I think it can take the two extra words.
I think that makes it better, though I suspect I'm approaching the stage of overthinking where I can't tell any more...
Anyway, thanks for your help, caco!