J.M.
S.,
Sweetie you need to realize two things. 1) Your a good mom. None of us would be on this board asking for help if we weren't. 2) The life of a man and a child and the perfect nuclear family, it's not in the cards for everyone and you can't make it happen.
I only have one child, but having a lot of friends with two, everyone feels the way you feel, no matter how many men are involved. It's hard to have two children, especially two young children. Then again, being a mom is tough. It's hard to love someone like you love your child and it takes a hell of a lot out of you. The fact is that as a mom, you do what you have to do and at the end of the day a big hug and kiss makes it all alright. It's alright to be worried and scared, but your going to do just fine. Don't let anyone tell you that you can't handle what is coming, espcially a man. Men don't know the amount of physical, mental and emotional strain that a mother can endure for her children. Your little girl does sound like a handful, but they all are. They are also all unpredictable. For all you know she may adore having a little brother, it may be what she needs in the end. It might be that this will give her the sense of family and belonging that she needs after seeing her parents spilt. I can't promise this will be the case, but why not give her the benefit of the doubt? You may find that she adores being a big sister and adores her little brother. Then again maybe not, sibling rivalry happens to all children. The thing is though, that you can do it. Don't let anyone tell you you can't. Giving up your daughter more, is just going to hurt you both. Don't do it. Follow your heart NOT your fears. Remember how scared you probably were as you raised your daughter, or when you first became a single mom. You got through all that and you will get through this. You can do it.