I found AMERICA and JOHN TRAVIS on the 1850 DIst. 1, Fayette Co., Kentucky Census - transcribed below:
Head of household, JOHN TRAVIS, age 26, born in Kentucky, occupation is "laborer".
Wife, AMERICA TRAVIS, age 23, born in Kentucky.
FRANCIS TRAVIS, female, age 21, born in KY.
JOHN TRAVIS, age 24, born in KY, "laborer".
WILLIAM TRAVIS, age 4, born in KY.
JOHN F TRAVIS, age 2, born in KY.
WILLIAM, age 4 and JOHN F TRAVIS, age 2, are the children of AMERICA and JOHN TRAVIS.
By the 1860 Census, AMERICA is not listed as living in the household, which indicates she has probably died. TRAVIS and his children are listed on the 1860 Lexington, Fayette Co., KY Census - transcribed below:
Head of household, JOHN TRAVIS, age 30, born in KY, his personal estate is worth $50, his occupation is "cartman".
Son, WILLIAM TRAVIS, age 15, born in KY.
Son, JOHN TRAVIS, age 13, born in KY.
Son, GEORGE TRAVIS, age 12, born in KY.
Son, CHARLES TRAVIS, age 9, born in KY.
Son, JAMES TRAVIS, age 7, born in KY.
Daughter, SARAH TRAVIS, age 4, born in KY.
Son, OLIVER TRAVIS, age 8 months, born in KY.
It appears that AMERICA had 7 "known" children within less than 15 years. Perhaps she died soon after the death of the youngest child, OLIVER.
By 1870 JOHN TRAVIS has died as I found the two youngest children, SARAH and OLIVER "OLLIE" TRAVIS, on the 1870 Lexington, Ward 2, Fayette Co., Kentucky Census, living at an "Orphan Asylum".
In researching the Kentucky birth and death records on Ancestry.com, I verified the following children as being children of JOHN TRAVIS and AMERICA JENKINS:
1. SARAH TRAVIS - born Oct. 20, 1856 in Lexington Co., KY.
2. JAMES TRAVIS - born May 24, 1955, died August 11, 1911 in Lexington, Fayette Co., KY; buried in the Lexington Cemetery.
3. GEORGE TRAVIS - born Feb. 27, 1858 in Lexington, died Nov. 4, 1910 in Fayette Co., KY.
4. MARY CATHERINE TRAVIS, died (age unknown) on July 6, 1859 in Lextington, Fayette Co., KY; cause of death is "teething".
5. SALLIE TRAVIS MORGAN - born about 1860, died Feb. 20, 1920 in Lexington, Fayette Co., KY. Spouse is JOHN H MORGAN; father is JOHN TRAVIS. She is buried in the Lexington Cemetery.
I regret I was able to answer your question. But from the information on the Census records and the approximate age of her youngest child, we know that she probably died in 1859 in Lexington, Fayette Co., KY.
I hope this information was helpful to you - and please remember, we all have "brick walls" in our family trees! Sometimes, it is just a "temporary" one - perhaps in the future you will learn the answer to your question.