No, you didn’t do anything wrong! I think the issue here is that you’re blurring the line between client and friend.
It’s not uncommon for clients who have been blonde for a while and choose to go darker for whatever reason, almost immediately regret their decision. That’s one reason why I try to persuade them not to go darker than a 6/7 if they’ve been around a 9/10 for ages as the difference can be quite a shock to the system.
It’s much easier to stay professional when treating someone as a client and ensuring that the final decision is theirs. And if they change their mind and want to go back to their previous colour, you must charge them for the pleasure. That way, you keep the whole thing on a professional footing and importantly, it keeps it less stressful for you.