Will it look weird if I say that I am interested in sociology, but my teacher says that I am interested in biology in my letters of recommendation?

Even if she did mention that you want to be a biology major, it’s unlikely to make or break a decision.

In many instances, though, biology is one of the most competitive majors because many high-stats pre-med students apply to it. If a school directly-admits to a major and you have ECs that scream pre-med, it’s possible that an AO will wonder if you are trying to game the system by applying to a less competitive major.

It is very unlikely to change a decision, though. These kinds of errors probably happen often. Don’t fret — it’s going to work out.