If your children are ready to see your girlfriend as their ally and not as a threat, it will help to create a strong connection between her and them.
Depending upon the age of your children, different activities may be appropriate. Some examples may be: shopping for ingredients then baking or cooking together, going to the zoo together, a sporting event. It is better to choose an activity that will give you something to do where you can also interact. A movie will be all of you just sitting next to each other quietly, while going to dinner will be quite a bit of pressure to come up with conversation. These latter two examples will be good activities for later on, but not for the first meeting.
