FFLAG also have a number of resources available for download on their website here https://www.fflag.org.uk/booklets-posters-forms/
Here is their list of useful booklets, click the desired title to go to FFLAG’s website to download:
How Do I Tell My Parents I’m Transgender
A Guide for Family and Friends – Transgender
How do I tell my children I’m Trans
How Do I Tell My Parents I’m Gay/Lesbian/Bisexual