It is not silly to be upset! You want to feel like your T remembers you and thinks you are important. Of course you would expect her to know your proper name after all these years. And perhaps adding to her being sick and cancelling, it feels even more important to be reassured that she cares about you.

Your T will probably want to listen to your thoughts. Will you tell her what you wrote here?

I am a good speller, but clumsy at typing and texting. Sometimes my finger slips and I don't realize the typo until the message is sent. Then I feel badly but it is too late. let's hope your T's mistake is just a silly misunderstanding!