In the women’s event, which offered Rio Olympic spots to those finishing within the 2:45.00-hour mark, Jane and Natthaya (formerly Saifon Piawong) crossed the finish line in 2:42.09 and 2:44.43 respectively.
The 32-year-old Jane finished 13th while Natthaya, a gold medallist at last year’s SEA Games in Singapore, came in 24th.
The Houston event was won by 25-year-old Ethiopian Biruktayit Degefa, who overcame a slow start to clock 2:26.07.
Thai veteran Boonthueng Srisang failed to qualify for the Rio Games from the men’s event in which the cut was made at 2:19.00.
The Thai timed 2:24.00 to end up in 27th place. However, he can still earn a ticket to Rio through other events.
Ethiopia’s Gebo Burka, 28, won the race in 2:10.55 to claim the fifth major marathon title of his career.
Jane and Natthaya are the first two Thais to qualify for the athletics events of the Rio Games.
They are also the first two Thai distance runners to compete at the Olympics.
Natthaya said it was like a dream come true because she is 37 years old and the weather in Houston was very cold.
She added, “I hurt my leg during the race and it was also hard to breathe in the tough weather. I am a bit surprised to have made it.”
The Amateur Athletics Association of Thailand hopes to earn more Olympic places from Boonthueng, Subenrat Insaeng (women’s discus), Khunanon Sukkaew (women’s 400m), Jirapong Meenapra (men’s 200m), and the men’s and women’s relay teams.
The country has never won an Olympic medal in athletics. Thailand’s authorities are aiming to have 37-57 athletes at the Rio Games in August.