A girl is giving mix signals. what's next step for me?

a girl (we work at the same place and know each other since 6 months) started showing interest in me. we are good friends.
we chat a lot, flirt with each other, she discuss about her family, what's happening in her life etc.
I also showed interest in her, it went well for a month time.
one day I asked her out (she didn't say no, but gave, may be someday kind of answer)
so I told I like her and she told me she is treating me as good friend (which is hard to believe because the way she treats me in public, her body language etc.)
she also told me that marriage thing is up to her parents (???), she has been in many awkward situation in past, lets leave it on destiny etc. and I said ok.
next day she told me she is feeling guilty for unintentionally hurting my feelings and I replied to her, I can't blame you, she said thanks.
now she knows I like her, she sometime show interest in me, sometime ignores me, sometime behave strangely, sometime behave very cool.
I also try to be cool, throwing jokes when we are in group and we do talk normally sometime like nothing happened.

what's running inside her mind? what's next step for me? back off? move on?

Some times the worse thing that can happen is for your dreams to come true. This sounds like one of those situations. If you get into a relationship with someone whose family will call the shots, you're setting yourself up for disaster.

Move on to a relationship where you can be an equal partner, not a crony to your in-laws.

I strongly agree with Rob