On the surface, family trees sound simple, but unfortunately this isn't always the case. Once a family starts to involve ex spouses, second spouses and step and half-siblings, condensing it into a family tree can get complicated. But there are ways to include former spouses in a family tree without making things too messy.

There are official standard methods of creating generation charts of biological ancestors, but if you're putting together a family tree for personal reasons, you can have a lot more freedom with it. You can even design your own key to indicate the different types of relationships in your family tree – for instance, a dotted horizontal line might represent a dissolved marriage, while a solid one means the marriage is still standing. One of the most common ways of denoting a divorced couple is to draw a horizontal line between the two ex spouses and insert a diagonal line into the horizontal line to symbolize divorce.

If you're creating your family tree for purely genealogical purposes, you need to include former spouses only if they involve a biological relation to you, such as a half-sibling. Some genealogy charts, like five-generation ancestor charts, include only ancestors and exclude siblings, meaning you'd include all of your ancestors regardless of whether they remained married, and you'd leave out any of their spouses who aren't your direct ancestors. However, if you're designing your own family tree and would like to include former spouses for personal reasons, you may do so at your own discretion.

Where there's a family with multiple marriages, there are often varying types of sibling relationships: full siblings, half-siblings and step-siblings. There are a few ways to indicate these relationships on your family tree. Consider a half-sibling relationship, for example. Perhaps your mother and father divorced after having one child (you), and then your mother remarried and had another child. The second child would be your half-sibling on your mother's side.

You would draw this section of your family tree as follows: Connect your mother and father with a horizontal line, then draw a vertical line downward from their relationship to the symbol representing you, their child. Insert a diagonal line through your parents' connecting horizontal line to represent their divorce. Add a horizontal line between your mother and her current husband, then a vertical line downward from their relationship to a symbol representing your half-sibling.

For a step-sibling, structure your family tree similarly, except draw the vertical line downward from your step-parent's symbol to your step-sibling's symbol. This indicates that the sibling is not biologically related to either of your parents.