Applying for PhD position to multiple professors in the same department I got interviewed by a potential supervisor but she said she couldn’t accept me because I have no research experience related to her projects. I still want to do research in her field; so I contacted some supervisor from the same department as her and will be interviewed next week.

I want to know if it is ok to contact another supervisor from the same department if she finds out about it.
It is ok, since she already told you no. It is your right to find new one and to apply to us many as possible positions. 
I think you should know that if you would like to work on someone's projects, it is highly desirable to have experience.