Thanks, Natalie and Sharon!
I'm sure glad I haven't been pulling baby daylilies!
And yup, I know what you mean about the way daylily roots look, Natalie. I just didn't know how well grown a baby would need to be to look like that. It worries me if it is nutsedge as it is in some cases very close to the daylilies. For now, I guess I'll keep weeding as best I can and see if the same weeds reappear quickly.