I have 4 kids and she has 1 kid from previous relationships we now have 2 together will it work?

I'm guessing since you already have two children together, you're comfortable with each other. People are different, it may work if you choose to parent your kids you have together and the kids you already have plus her kid with the same attitude and love then you should have no problem with having kids who are not yours by blood bonding with your kids that you already had from someone else.