I believe "Relationships" would provide a good way of solving what you're asking for, although I may not be fully understanding things. Here's how I'd get started with using relationships....
Start by creating topics for Mom, Dad, and each of the children. Do the same for Aunt and Cousin. You can use the Quick Create mechanism <ctrl+Q> to put the topics into place with just their names, which is all you need to get started.
View the Mom topic and click on the "+" button to the right of Relationships in the Transitions Pane at the far right to show the Relationships window. Select one of the children in the topic list on the left. In the droplist at the right, select "Family Relationship". Then in the droplist to the right of that, select "Immediate Ancestor Of". In the description area, you can enter details like "Oldest child", "Firstborn son", or whatever details you want. Then click the OK button.
You should now see the relationship in the Transitions Pane on the right. You can do the same for all the other children if you wish. Plus you can setup the same basic relationship from Dad to each of the kids.
You can create a different Family Relationship between Mom and Dad, using the "Union With" relationship type. This designates Mom and Dad as being co-parents of the children.
If you want to establish an explicit Sister relationship between Mom and Aunt, that would require creating a topic to serve as their shared parent - you only need one parent. Alternately, you would create a new Family Relationship using the "Other Family Of" type. The same would be done between the Cousin and Mom, but you'd create an "Immediate Ancestor Of" relationship from Aunt to Cousin.
If you prefer, you can use the "Parent Of" and "Child Of" relationship types instead of the ancestor versions. This distinction is important when dealing with things like step-children, adoptions, etc. If you have a bunch of mixed families and want to clearly track LINEAGE as distinct from the family unit (e.g. bastard children of nobility), then its critical to accurately choose between Parent/Child and Ancestor/Offspring, since those distinctions are important when viewing relationship diagrams.
Once the relationships are established, you should be able to view the Relationship diagram for the family by starting with Mom as the active topic. From there, click on the button in the header region of the topic (next to the edit/save/etc buttons) to show the relationship view for the topic. Then select Ancestor/Offspring for the relationship type.
The key benefits of using relationships like this are:
(a) They are individually revealable, so you can reveal each one as the players discover the relationships. This can be really handy for intrigue games with bastard sons of kings maneuvering to take the throne.
(b) You can annotate them with descriptions to detail the relationship more fully.
(c) They behave just like links within snippets, so you can click on them to navigate through your content.
(d) You can view relationship diagrams that can be extremely helpful in a variety of situations.
The key limitation of relationships is that our diagramming logic is good but not sophisticated at this point. So we aren't yet able to do complex family tree diagrams. That's on the todo list, but we haven't gotten there yet. The diagrams can be extremely useful, but they aren't as good as a dedicated genealogy program, since Realm Works offers lots more beyond what a genealogy program offers.
Hope this helps!
