I just finished Life In Early Texas: The Reminiscences of Mrs. Dilue Harris. Dilue Rose Harris was an 11-year old in 1836. Her father was a doctor/farmer who settled his family in 1834 on the Jesse Cartwright league midway between Sugar Land and Richmond.
Her account of the Runaway Scrape is very interesting. They got as far as Liberty when they learned of the victory at San Jacinto. (They heard sounds of the battle. Her father was a former military doctor and recognized the din of cannon fire.)
They had a very rough time -- her baby sister died of an unidentified disease while they were camped at Liberty -- but she said other refugees suffered more than they did.
As they made their way back home, they stopped at the San Jacinto Battle ground on the 25th. She described it as grewsome. She had a chance to go see Santa Anna, but declined. She'd lost her bonnet and had to wear a table cloth to cover her head in the bad weather. She didn't want to be seen wearing a table cloth by anyone she knew.
They picked up a lot of news while at the battle ground, including this account of Old Whip. (She thought Allen Vince owned the horse, but most other accounts say his owner was William Vince.)
We stayed one day on Sims Bayou. There were more than one hundred families, and all stopped to rest and let the stock feed. We met a Mrs. Brown (a Scotswoman) who was living at William Vince's when the Mexican army crossed the bridge. They took possession of Allen Vince's fine black horse. Mrs. Brown's son James, a lad aged thirteen, went and mounted the horse and would not give him up. The Mexicans made the boy a prisoner. His mother came out and asked for Santa Anna. Colonel Almonte came out and asked in English what he could do for her. She told him she was a subject of the King of England and demanded protection. Almonte assured her that she and her children would not be hurt and ordered her son to be liberated. Santa Anna's servant put a fine saddle on the horse. It was ornamented with gold and had solid gold stirrups. When the captured plunder was sold at auction, the Texas soldiers bid it in (made the winning bid) and presented it to General Houston.
It appears that William Vince never got his saddle back. In another section of her memoir, she described Santa Anna's capture.
General Santa was captured the next day after the battle. He was seen by Captain Karnes to plunge into the bayou on a fine black horse. He made his escape from the battle ground on Allen Vince's horse, but not on the fine saddle. He (the horse) was taken to headquarters and after a few days was restored to Allen Vince. James Brown (the young boy mentioned earlier) pointed out the horse.