Is she hinting that she wants to get married?

She was offended that you snooped under her bed. You then made a joke about it instead of apologising. Hence, you were asked to leave. Lots of women enjoy looking through bridal magazines. There are numerous reasons why she could have them and not necessarily that she wants to marry you. Silly man! Thinking it's all about you. Your first, most important step now is to apologise. Say nothing more and don't mention the magazines. Wait for her reaction to the apology. If she doesn't bring up the magazines, then you sure as hell better not. Good luck.