Regarding Purification Bath after wet dream...In this condition can I just wash my body to attain purity?

What should a woman do when she wakes up and finds some fluid but unable to determine whether its mazi or mani? She does not recall any wet dream but remembers other dream which she saw during sleep. However before sleeping there were sexual thoughts but the fluid that was secreted at that particular time was properly washed up. In these circumstances, does the ghusl become obligatory? One more thing, is it compulsory to wash hair every time to purify myself because at times I daily experience the above stated problem but you know daily washing of hair can damage them? In this condition can I just wash my body to attain purity?