First of all, I am sorry for the loss of your mom. That must have been very hard, and I can just imagine the void it left in your life. (((HUGS)))
I have the same longing, but for different reasons. My mom is still very much alive, but has never been the loving mother anyone would dream of. She is quite a selfish person with a difficult character, and we never had a good relationship to start with. Now that I am an adult and mom to my own children, I realize even more just what I didn't get from my own mom, and I long for a mother-daughter relationship such as the ones we see in movies or read about in books. I also do feel very lonely as the only woman in the house, and since I cannot turn to my mother for comfort, it makes the feeling even harder to deal with.
The truth is though, even if we did have a daughter, we would not be guaranteed that relationship. There is no way to predict how our daughters would be and if their personalities would be compatible with ours, or if we would conflict. I see it all the time with my sister... She did get a girl first, and her DD is 7 years old now. They get along still, but they do have their moments when I think "wow, the teenage years will be hard!".
Anyway, I know that's little comfort to you right now, but I did want to let you know that I fully understand. ((((HUGS))))