Queen of the States by Josephine Saxton

Meet Magdalen, a woman who is on her own planet, out to lunch and on her own trip...

She moves through time and space, from a private mental hospital to an alien spaceship where she is interrogated about human behaviour and the function of sex. Is Magdalen mad, or have the aliens really landed? She weaves her way through the fantasies of those around her - husband Clive, psychiatrist Dr Murgatroyd, lovers, friends and friend's lover - until, finally, she can reclaim her own existence