https://play.google.com/store/apps/details?id=com.lbrc.PeriodCalendar&hl=en... The tracking guide and the period calendar can help her keep track of her monthly period.
https://play.google.com/store/apps/details?id=com.mydearjournal This is a place that a girl can write down her thoughts and and emotions on how she is feeling about her first menstrual cycle and her first period kit. She can also share her feelings with a trusted adult.
https://www.girlshealth.gov/body/puberty/index.html This is a reference so that adults and children can get the correct information about her menstrual cycle and the changes that are going through her body