The mother of 10-month-old Lisa Irwin of Kansas City, Mo., admitted that she was drunk when her daugher disappeared and changed her earlier story about when she last saw the baby, who has been missing for nearly two weeks now.

Deborah Bradley told Peter Alexander of NBC's Today show that she expects to be arrested -- a concern she has expressed before.

My main fear is that if they arrest me people will stop looking for her. And then I'll never see her again, a tearful Bradley told Alexander.

Surveillance footage from a local liquor store showed Bradley buying wine the last day Lisa was seen by her family. Bradley was accompanied by a man who was later identified as her brother. On Sunday, Bradley told Fox News she had several glasses of wine with a neighbor later that night.

Bradley told Alexander that she consumed enough to be drunk.

When asked if she felt she might have been incapacitated enough to harm Lisa, Bradley insisted not.

No, no, no,'' she told Alexander. If I thought there was a chance, I'd say it. I don't think that alcohol changes a person enough to do something like that.''

Since Lisa vanished, Bradley had maintained she last saw her daughter at around 10:30 p.m. CDT on Monday, Oct. 3. But now Bradley says she last saw her at around 6:40 p.m.

It's unclear why Bradley is coming forward with this new information now.

(Being drunk) would explain why she didn't hear the baby monitor, she didn't hear the dog barking,'' former district attorney Jeanine Pirro told Ann Curry on Today. People were believing her because her story was consistent. Now she comes out with, 'The last time I saw my baby was at 6:40 and by the way, I was drunk.' This isn't the kind of thing that you want to bring out after the fact when time is essential here.''

Lisa's half brothers -- who are eight and five years old -- have largely stayed out of the investigation. Their family has refused to allow police to re-interview them despite the fact that they reportedly heard unusual noises the night of Lisa's disappearance.

They said they heard noises, but I don't know if that was before they went to sleep or after,'' Bradley told Today. I have not sat down and talked to them about it, specifically to not have to put them through anything else.''

An anonymous benefactor has posted a $100,000 reward for information leading to Lisa's safe return or the arrest of her kidnapper. It's unclear if this is the same benefactor who reportedly hired private security consultant Bill Stanton to help investigate the case.

Stanton told Fox News he's hopeful this child is safe and alive.

About 25 Missouri National Guard officials joined the search for missing baby Lisa on Sunday, Fox News reports.

Watch Lisa's parents on Today: