Classic Knits by Erika Knight Gloves HELP!

Hello! I am new to this forum so hello to everyone. I joined because I am completely stuck trying to knit a pair of gloves in Erika Knight’s book [U]Classic Knits.[/U] I did fine up until near the bottom of the left column on page 92, where you knit the main part of the thumb of the gloves. What I am stuck on (and I don’t know if I am reading it wrong or just misunderstanding) is how can I knit the rows in just those 18 or so stitches when my needles are still through the rest of the glove on both sides? Won’t it not be able to stretch that far? Should I remove the needles and put some sort of holder in the side sections?

If anyone had knitted these or tried and can help, please do!! Thank you so much!!

I don’t have the book, but when you knit thumbs, usually the thumb stitches are put on a spare piece of yarn or holder while you finish the hand. Then, when you do the thumb, you have only those stitches to work with.
However, if it’s done differently, and the other stitches are still on the needles, you can just work the designated ones back and forth. When you’re working in the round and have to switch to back and forth, turn your work and purl back as if you’re working those stitches on 2 needles.