while struggling not to blame but everything show otherwise

Last week I left work realising that my credit card had desapear in my purse I remember that same morning put it back in my purse loose in the pocket, but as soon I look in my purse it wasn't there anymore, nothing was taking from it that was the only thing loose. So I feel terrible but there is only one person that I could think of that have might take it but at the same time I am in betrayal since she is very nice to me. But there is no one else that have access to my purse since I leave it in the office where she work just beside her desk usually I am there with her but that day I had a lot to do elsewhere and I left my purse there. First thing I done the next morning after making sure I hadn't put it anywhere else I call to report a stolen card. Since then I don't bring my purse inside or I remove all important stuff from it. But today I was working in and out of her office, but there is one time I came back walkin the office and haven't seen me arriving lifting up her head she quickly put something a card ... a credit card in her purse same color as mine.. really akward moment I didn't know what to say' i didn't want to loose whatever we got between us.