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?

I think you should take the help of your ex-wife to break the news to your daughter since she is staying with her mother. She needs to be get the feeling of acceptance from your wife as well. Because if your ex-wife is not in agreement with you then she is going to pass on her resentment to your daughter as well. So, I think you can take the help of your ex-wife if you are on friendly terms, else talk to your daughter that you are going to stay with a friend of yours. Since, she is just 6, I do not think giving too many details would be a good idea as at this age kids do not otherwise also get the whole idea about marriage or re-marriage clearly. So, do not make things complex for her and slowly unfold the things as she grows up. And you can introduce your daughter to your new wife saying that she is your very good friend. Eventually, when she will meet often and as she grows up, you can discuss things with her depending upon her maturity level, and can decide how much to reveal and how much to hold back till she can imbibe what she hears. And as far as your partner's daughter is concerned, I suppose after marriage three of you will be staying together, so it is very important for you to establish a bonding with your step daughter else it may cause many difficult situations for you two as a couple. Kids do not accept it easily, the coming of a new man or woman in either of the parent's life, so you have to be friends with her before you decide to get married. Kids are very possessive about their parents and she would only be willing to share her mother's love with you, if and only if she likes you and forms a bond with you. So, I would stress that you need to develop a repo with the little girl.