It takes way too many clicks to add multiple family members, and link them to the same set of parents. There are several things that could improve this.
1.) When adding a father or mother, offer the most recent person or persons chosen in the same dialog as a shortcut choice.
2.) When adding a link to a father, mother or spouse, the first dialog offers new person or select from list. The "select from list" includes a search box. Please add the search box to the first dialog, to skip the extra step.
3.) Create an "Add multiple children" dialog, where the children added are all assigned to the same set of parents.