Collins, who represents the West Side, had been considered in some circles the odds-on favorite to replace Hendon.
The Democratic bosses who selected Collins deny that the process was in any way fixed as they chose her from a field of 13 candidates.
The applicants were considered by the party's central committee members whose wards included parts of the 5th senatorial district. Representative Collins was the only elected official who applied, an indication to some observers that she was a prohibited favorite.
"I think it's important that we fight for the things that we believe in in our community and yes, our community is diverse. And that's why it is important to keep diversity, to keep a balance in the city of Chicago," said Collins.
Other contenders included Patricia Van Pelt Watkins, who recently ran for mayor and lost by a large margin, and Scott Lee Cohen, who last year was the Democratic nominee for lieutenant governor but then resigned before running later in the year as an independent for governor. The committee members decided not even to consider Cohen as a finalist.
"They consider me, I would say, a rogue because I am not owned by the Democratic Party. I have my own mind and my own thinking, and my only concern is to represent the people and not the party," said Cohen.
Collins will be sworn in Wednesday when the state Senate reconvenes in Springfield.
"Things that are on the agenda is the budget. Right now we have $8 billion of unpaid bills that we are trying to figure out," said Collins.
"The fix was not in. Everyone up there had their thoughts about who was best qualified to be the senator of this district, and we just finally a few moments ago arrived at who that person should be," said Jesse White, Ill. Secretary of State.
A smaller number of central committee members will convene in the next few days to select a replacement for Collins in the state legislature. There could be some controversy involved in that process because Collins has already recommended that she be replaced in the state House by her daughter.