Final answer:
Babies may begin to recognize their siblings' names between 12 to 24 months, as they start to understand words and commands around their first year and show self-recognition and the ability to name familiar persons in the second year.
Step-by-step explanation:
Understanding when babies can recognize their siblings' names involves understanding the stages of their language and cognitive development. By the time a baby is 6 months old, they are starting to recognize sounds and engage in vocal play, possibly making sounds like "mama" or "dada." Although this indicates the beginning of language recognition, it's generally by the age of 12 months that a baby may start to use one- and two-syllable words and understand several other words. This is the time they can also follow simple commands if associated with gestures. As they reach 18 to 24 months, babies' cognitive abilities are further developed, and they begin to show self-recognition and the ability to name and point to themselves in pictures. This period of their development would likely coincide with their ability to recognize and identify their siblings by name - if they have often heard the names being used by others in the family. Therefore, while there is no specific research pinpointing the exact age babies can recognize their siblings' names, based on their cognitive and language development milestones, it is reasonable to infer that babies may start to recognize and respond to their siblings' names somewhere between 12 to 24 months of age.