Ugh so fed up

Yesterday I went to the dollar store for some girl stuff. And the manager comes up to me ace tells me I was band from the store from stealing. I looked at her confused and then she tells be the girl that I was with which I wasn't her friend she is my boyfriends brothers girlfriend. I took her awhile back when I was 6 months pregnant too get some pads. And apparently she was stealing and I didn't know she was. I told the manager I had nothing to do with it do to me having a job i could pay for the things I got. Plus she is a crack head and got her own baby taken from her.

Should i tell her or let her get caught?