Pedigree Forge will usually automatically recognise that a child was part of a multiple birth—so long as the dates of birth are the same. The convention on family charts is that multiple births are drawn linked to their parents from a common stem, whereas other siblings have a stem each:
In the following example, Kate and Grace have been automatically identified as twins, because they have the same date of birth (1856):
If no dates of birth had been entered (perhaps they weren’t known), Pedigree Forge would not have been able to pickup that Kate and Grace were twins, although this fact might have been known.
The can be manually set to be from a multiple birth, using the “Families” tabe of the “Current Person Other Detail Dialog”, accessed from the ⋮ button, located next to the name field:
Note: both Kate and Grace have to be set as being a multiple.
The “Not multiplet” check box can be used in the reverse situation—to stop Pedigree Forge from joining too children together as a multiplet—perhaps we only have approximate years of birth for two children which were within the same year (Pedigree Forge would assume they were twins), but if we know that isn’t the case, we can flag them as not a multiplet.