No, you still couldn't get in-state tuition in Texas as the child of an illegal. Those children must attend Texas schools for three years immediately preceding their application for in-state tuition.
But you could move to Texas and reside here one full year to get in-state tuition. 1 year versus 3 years. You get preference over them.
A. The following persons shall be classified as Texas residents and entitled to pay resident tuition:
1. a person who:
a. graduated from a public or accredited private high school in this state or received the equivalent of a high school
diploma in this state, and
b. maintained a residence continuously in this state for
(i) the thirty-six months immediately preceding the date of graduation or receipt of the diploma equivalent, as
applicable; and
(ii) the 12 months preceding the census date of the academic semester in which the person enrolls in an institution
(Note: An individual who is neither a US citizen nor permanent resident must complete and submit the Affidavit).
Form: http://www.admissions.txstate.edu/future/residency.html