Aw mama, ang hirap talaga ng transition stage, a few of us went through this with our introverts, and honestly, pushin lang sila agad usually backfires, kaya better to take it slow and let her warm up sa environment muna. With my daughter, I realized na rewards and pressure lang ang nagpasama, so I shifted to just celebrating small things, like "yay, you sat near the teacher!" instead of "why didn't you finish writing?", at parang nag-relax siya over time. Since she's shy and may baby brother at home, siguro she needs extra reassurance na safe ang school, kaya baka pwedeng go with her on some school days kung allowed, or talk to her teachers na mag-ease in lang siya instead of forcing participation agad sa flag ceremony. The writing thing will come naturally when she's ready and confident na, hindi mo na kailangan mag-reward; some kids just need more time to process things than others, especially introverts, at yan normal lang sa preschool level talaga.