Well, I just found video of her singing it on stage. But better than that, it's from the closing night performance of the Broadway production. (The video identifies this as the closing night of the "original production," but that can't be the case, since Glynn left the show and was replaced by two other actresses. However, after a national tour, the musical had a "return engagement" on Broadway for a couple months, and Glynn recreated her original starring role. I suspect this is from that run.)
Also making the video fun is that "The Bus from Amarillo" is the final number, so we get to see the last curtain call. Unfortunately, the video cuts out before the stars make their appearance, but still, it's nice to see.
The sound quality is lousy, but if you want to refresh yourself on the lyrics, you can click the link above. The video cuts out a few times, but it's not problematic, and the song picks right up where it left off.