Shawn,
I meant to post a reply a few days ago, but I just got back from a trip to Gettysburg. I've also got a copy of "The Bloody Fifth" and it is a very good book (except a few spellcheck errors here and there). I think you may have skipped ahead a few pages though when you made reference to the flag in your post. There are actually 2 or 3 other flags that the 5th Texas used before this one that Schmutz talks about. On page 14 he made mention of a company level flag for Co. K (some other authors say this was drafted briefly as the regiment's 1st flag, but you may or may not want to count this as a regimental flag.
The 2nd flag (and the unit's favorite throughout the war is first mentioned in pages 33-34. I won't quote the whole passage here, but you can find it and the footnote about it listed on the pages I mentioned. The flag that this is talking about is sometimes called the "Lone Star and Bars" for the 5th Texas (not to be cunfused like some authors have been with the Lone Star from the 1st Texas) that was commissioned in Richmond on 9/31/1861. This flag still survives and can be viewed here...https://www.tsl.texas.gov/historicflags/4042FifthTexas.html
This flag was soon replaced when the army was trying to standardize the new ANV patterns of battle flag, but after the Seven Days fights (when the flag from Mrs. Young was sent to have battle honors added to it), some members of the regiment pulled a bit of trickery and switched the Lone Star and Bars so that it was carried by the regiment at 2nd Manassas and Sharpsburg. Full details of the incident, and Hood's displeased response when this flag was unfurled at a review can be read on pages 140-141 of "The Bloody Fifth". Also not that while Don Troiani shows two flags in use at 2nd Manassas in one of his paintings, only the Lone Star and Bars was actually carried.
The 3rd flag for the 5th Texas was a silk ANV style flag made for the unit by Mrs. Wigfall. More details can be found on pages 48-49 of "The Bloody Fifth". This flag appears to be lost to history, but little bits are known about it. Apparently it was made and presented at the same time that another was made by Mrs. Wigfall and her daughters. These two were given to the 4th and 5th Texas, and it is presumed that they were fairly similar. The silk ANV "Wigfall" flag of the 4th Texas survives today and is in the collections of the UDC...a good image of the surviving "twin" flag from the 4th Texas can be seen here...http://webzoom.freewebs.com/coh4thtexas/photos/Original-4th-Texas-Battleflag/flag%20correction%20arranged%20and%20described.jpg
This ANV flag of the 5th Texas was apparently battered pretty badly and had its colors fading so that it stopped being used by mid-June 1862 (p. 49 "The Bloody Fifth").
The 4th flag is the one that you listed (p. 91-92 "The Bloody Fifth") made by Maude Young. More information on the original is listed here...https://www.tsl.texas.gov/historicflags/4047FifthTexas.html
Apparently the 5th Texas solicited people back at home to make this flag, and it was received by 6/14/1862 and started being used right after, but was out of action for a while receiving battle honors which is when the Lonestar and Bars was brought back into use briefly. This 4th flag was used until it was sent back to Texas sometime after Darbytown I believe. It is also this flag that my wife's ancestor was killed while carrying at Chickamauga.
It is also interesting to note that there is one other flag nearly identical to the 4th flag made by Maude Young. This other flag is listed as that of Co. G 16th Texas Infantry, and can be viewed here...https://www.tsl.texas.gov/historicflags/4057CompanyG.html
While nothing has yet been linked between this flag and Mrs. Young, the construction is so close to identical (down the the unique chain stitched edges of the stars, and number and style of the eyelets for attaching the flag), that it is highly likely that this flag was also made by Mrs. Young, perhaps even at the same time as that of the 5th Texas.
I hope some of this information is useful. As you keep reading "The Bloody Fifth" you'll find that there are many more references to the flags of the 5th than I have listed here and they go into much great detail that I have shared here. I highly recommend that anyone who is interested in the flags of the 5th Texas get a copy of this book, and also volume 2 which is due out next year.
Josh Bucchioni