'When I came back, she was there, and three other women had also arrived' is good, although I prefer 'She was there when I came back and three other women had also arrived'. Even better 'She was there when I came back along with three other women'.
Drop 'another', drop 'more', they are awkward to use in this instance. Go with 'other' instead.
She was there when I came back along with three other women.-- This is a bit different, though; here, all 4 women came together. The tone of the original is that she arrived separately and perhaps earlier.