To steward a good step sibling relationship it's important not to push the kids on each other and it's important to honor their differences. Try to find common interests, try to come together on things as a family but let each kid know that you will honor their own individuality and that we now have a different circumstance that we're all going to work best for it together but they have to be able to communicate with you. The challenges sometimes there might be competitions among sibling trying to win their parents love and jealousy among sibling for the parent's attention. It's important again to each parent communicate that they are there for their child that you're honoring and respecting their differences, that you're listening to their needs and that you are going to make the best of what might be a difficult situation but that you'll go slow and be patient and it's great if you do common interest between your siblings and new siblings and at the family as a whole. Maybe everyone like skiing of there is something you could do as a family.