"I was taught that you never ever out a convert. Even if everyone knows that so-and-so converted, it is a sin to point it out to anyone."I don't agree with that necessarily as the halachic standard, but it's probably the correct politeness standard. But on the other hand, there are a lot of factors we don't know:
Is her conversion part of the lecture?
Did she approve the text?
Does she normally list herself in this way?
Last I heard in the comments section, we don't know these answers. But, as was probably intended, proclaiming the speaker to be a convert will undoubtedly bring a larger crowd than would otherwise show up. And that's good for her parnassa.