I hate to tell you, but in my experience with my oldest DD the IQ scores at a later date may level off. She was much like your child at 16 months, and although she still performs at a HG+ level, especially in non-verbal reasoning and her VCI, she only tests MG on most tests and would not qualify for separate gifted schools. (She had the highest math average for her school last year in top-block 6th grade pre-algebra and is consistently the highest in STAR reading scores/AR points in her school.) In her case, however, it is likely a 2E situation with written expression/non-verbal working memory/dysgraphia/anxiety issues coming into play.