shy

For her, the outside world still seems new. Maybe she has been at home more. Unfamiliar environment makes them become shy sometimes. Take her to playgrounds, let her find friends her age, do external activities with them.

Bring her outdoors, perhaps sand play would be good and can involve her with other kids as well :) As she grows older can expose her to more sports activities

Maybe start her with play dates and keep Adding the number of playmates she has. She might need to learn to open up and be more sociable one step at a time.

Bring her out more often (eg: playgrounds, or kid friendly Malls/restaurants) so shell can mingle with other kids at her age, older or younger too

I hope this article helps you : https://sg.theasianparent.com/kid-shy-around-people-improve-social-skills-tips

I also having the same issue. My boy keep quite when my friends talk to him or teachers asking him a question.

Being shy not necessary means she is not confident ba. Some kids are just more introvet and slow to warm

bring her out more often, start with a small playground, if possible play dates with friend's kids

Socialize. I socialize my dog too. They don't call dogs as fur-kids for nothing.

Give her some time and don't force her, when she is ready she will interact