By the time a trans person comes out to you, they have already done hours, weeks, and YEARS of research, questioning and soul searching.
Don't say "are you sure?"
Say "how can I help?"
The biggest regret any of us have is that we didn’t start soon enough. Especially when we knew that’s who we were all along. All of those wasted years. But always remember it’s not too late to start so don’t think life has passed you by at any age.