Kid accidentally put old used straw which she found in playground in her mouth i quickly removed it should i be worried?

No worries : Don't be worried but be watchful for abdominal cramps and any changes in bowel activity

Common problem: Kids are forever putting things in their mouth like dirt,bugs.toys. unclean fingers, etc. It is so common that it becomes part of the day to day of most parents. I wouldn't spend much time worrying about it.The kid might get loos stools, but most don't for some reason. Just fuss at her a bit and let it go.