If a child wants to take drugs and have surgery, it is absolutely the parents right to know. This is not the same as having a crush on someone.
It is the parents' responsibility to do the best for their children, and this includes making sure that young pre-teens do not make irreversible decisions that they will later regret.
Children change their minds all the time - parents know this. One of the most disgusting and insidious aspects of the whole "trans child" ideology is the painting of parents as some sort of evil enemy when for the overwhelming majority of families, they love their children and want the best for them.
This family friend does NOT know everything about that child, and it is absolutely irresponsible to encourage a child to keep secrets from their parents, a confide in another adult, especially when that particular adult is necessarily keen on validating trans identities. This is more about the adult's needs, not those of the child.
It looks very like grooming to me.