1. What is meant by 識嗌? 識嗌 "baba" "ma ma" doesn't necessarily meant they know what they're meaning. The baby may simply imitate what they always heard of, but isn't specific. My son imitated baba since he was 4 months and mama since he was about 6 months. But now he randomly says mama but most of the time baba, but not actually talking to baba.
2. Do more crawling than walking is actually better for baby's brain development. No worry before 1 years old.
3. My son loves to say "jer jer", referring to my maid, very specific ga!