i am in a relationship and my partner has a 10 year old daughter from her previous marriage. i also have a 6 year old girl who lives with my ex-wife. we are planning to get married, but not sure how to break it to the kids. any suggestions?

the only way to do so is to first individually talk to your own kids and then introduce the kids to the partner, if not already done. be very careful though when you guys talk to your kids, as they will be very nervous, scared, anxious, and may even feel guilty that they may in some way be responsible for the breakup. spend a lot of time and be understanding. and give it time.