I think I agree with lizard, just let her breathe a bit and then tell her the truth and how you feel and even though you went fast that you don't regret it. Tell her maybe how that you don't want something like that to get in the way and that you can work things out with the kids by making a schedule and not always being with her. Like you MAKE time for her and the kids where you are out of the picture for just a little while. This way you can stay with her while she still has time for her kids.
Just have a good talk with her I'm sure you can work it out.
I don't know about the age gap, you're a bit young to know what you want, but I'm not the one to discriminate on age. Go with your heart.
~The 3 things needed for Happiness: Something to do, Something to love and something to hope for.~
I am no expert, take everything I say with a large grain of salt.