The boys haven't yet been told their mother is dead, according to family members.
"I thank God my two grand-babies survived," said Denise Washington Hicks. "The older one is not really speaking but the baby seems like he knows something."
Tristian Hicks was rushing her boys to school when she drove around the crossing gates to beat Train 302 on the Rock Island Line. The minivan flipped on impact and the 26-year-old mother was killed.
Her sons -- 4-year-old Jayvon and his brother JonKing -- were transported to area hospitals. JonKing, whose sixth birthday is this week, has two broken legs. Family members said he'll have to re-learn how to walk.
At JonKing's school, Higgins Community Academy, students and faculty prepared get-well-soon and birthday cards.
"We've had the counselors talk to all of the teachers because they're very grief-stricken about the situation," said Asst. Principal Sam Gipson.
The Hicks family said it hopes the tragedy will raise awareness and prevent another senseless death.
"Don't ignore the signs. Don't ignore the lights and the gates because in this case it cost my sister her life," said Taja Hicks.
Metra officials said this year's 24 fatalities include four in a vehicle and 20 pedestrians. In 2011, one person died in a vehicle while 19 were pedestrians. Of the 24 deaths in 2010, just three were victims in a vehicle. In 2009, 14 pedestrians were killed and another was in a vehicle.
The transit agency said most of the deaths are suicides and not people running gates.