I would tell her as much of the truth as she can handle and needs to know. Why can't you tell her that you aren't working at x any longer, however, you are looking for a new job?
I know someone else who lost their job and didn't say anything to her kids, but she didn't want to share with her children the poor decision she made to lose her job. Her kids were calling every number they could to figure out if she was still there, so they knew anyway. She found another job and I am certain they now know their suspicion was correct and their mother lied to them.
Just tell her and if she asked why she is still in aftercare, let her know that it is because you will be in search of a new job and you need the time alone to do this.
Best wishes.