LifeLines 3.0.2 has relaxed most of restrictions on family structure that were imposed by earlier versions. For example, a family record may have more than one parent/spouse of the same sex; a person may be a child in more than family. This is a controversial issue. Some users insist that family relationships should imply biological relatedness, and that all other relationships should be handled by different means. Others insist that non-traditional families (any number of parents/spouses of any sex) should be allowed, and that children can be members of more than one family (eg, natural family and adoptive family). LifeLines no longer takes a position on this matter; you are free to set up families any way you like; the operations that add spouses and children to families no longer check for non-traditional arrangements. It is possible that a future release will include a user option to either disallow or to ask for confirmation about non-traditional relationships.

LifeLines provides features for merging persons together and for merging families together. The person merging feature is accessed from the tandem person browse mode, and the family merging feature is accessed from the tandem family browse mode. You browse to the two persons or families you want to merge and then use the j command. Merging is necessary when you discover that two or more person records, or two or more family records, represent the same person or family, respectively.

Versions of LifeLines prior to 3.0.2 required that persons and families meet certain criteria before they could be merged. The criteria ensured that the merged persons and families would still meet traditional family structuring rules. With the relaxation of the structuring rules, restrictions on merging have also been removed. It is now possible to create non-traditional relationships by merging traditional persons and/or families. For example, if you merge two persons that happen to be children in two different families, the merged person will be a child in both families. If you want to maintain only traditional relationships in your database you may have to makes further to changes to relationships after you complete a merge operation.