Can 14 mos old develop sleep apnea?

Yes: Unlikely but it can happen. At this age i'd be more concerned about a neurologic deficit causing central sleep apnea. If there is any concern, an overnight sleep study should be obtained.

Yes: It would most commonly be from large adenoids maybe with large tonsils. There are other causes also. This is not uncommon even in young children.

Depends on what type: In children with loud snoring most always the cause is due to adenoids and tonsils. However, occasionally children can also have central apneas where there is no struggle to breathe or associated snoring. It is as if they just forget to breathe. If you are observing abnormal sleep breathing, remember what you see and tell your pediatrician.