This parent sounds like precisely the kind who would make her child "detransition" under duress. The kid is likely still trans, but is now closeted. Their mental health likely took a major hit when their mom forced them to recant. Sadly, the likelihood of them thinking about suicide or self harm also jumped. This isn't just speculation: it is backed by numerous studies.

https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2789423

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5630273/

When trans kids are supported, their quality of life goes way up and mental health improves.

https://www.washington.edu/news/2016/02/26/transgender-children-supported-in-their-identities-show-positive-mental-health/

Any policy that supports kids in their identity without informing the parents is put in place because parents who are not supportive have been known to beat the everliving shit out of their kids or subject them to intense psychological warfare, if they don't kick them out of the house and disown them on the spot.