Our names are important. Using names properly is a sign of respect. I do believe what happened is different than someone you just met making an understandable error or someone you've known for a while making a typo.

In this case, you've been her client for five years.

I would absolutely expect her to know and carefully use your name correctly.

I would tell her how you feel.

I don't think it's unreasonable to feel upset at all- remember- it's not like you just went and vandalized her office because of it- all you did was feel upset, there's not a thing wrong with that.... using names properly is the respectful thing to do.

Of course she did not mean any harm, but... when we've known someone for five years... it can certainly be unintentionally hurtful nonetheless to have them mess up something important, and names are important.