The spouse and children may accompany the primary L-1 visa holder to the United States. The children must be under the age of 21, however.
The marriage must be bona-fide (in other words, it cannot be a “common law” marriage or a local equivalent, and it cannot have been entered into for the sole purpose of obtaining immigration benefits). Please note the the US government now recognizes same-sex marriages as bona fide.
Only the spouse and children of the L-1 visa holder are eligible for L-2 status. The L-1 visa holder’s parents, for example, are not eligible, even if the L-1 visa holder is their primary caretaker.