After just having our forth son between us and one a daughter from my husbands first marriage I desperatly want a daughter of my own I love my step daughter but it not the same as she was 10 when I met her I was wondering if there was any way to help this happen

To try and increase your chances of having a girl... google "Shettles Method". It is the most popular guideline on "choosing" sex. In a nutshell... the "male" sperm are smaller, lighter and faster than the "female" sperm. But the female sperm aren't as fragile as the male sperm and tend to live longer. If you are wanting a girl, try to have sex as far away as possible from ovulation while still allowing conception. By the time you ovulate, most of the male sperm will have died, and only female will be left.
But again, Google "Shettles Method" to get more info