@tanguatlay,
You are correct, Tanguatlay. The speaker is talking about the Principal to the audience, and therefore uses the third person. This is the standard way of formally introducing someone to an audience.
"First of all, I would like to express my sincere appreciation to the Principal of St Joseph School, for coming to our school to grace the occasion despite her extremely busy schedule. She [or name e.g. Mrs. Jones] is well known for her notable contribution to education in our community, and it is a great privilege to have her here today."
I would just add that those schools [mostly religious] which are named after saints are usually (but not absolutely invariably) named with the possessive, e.g. "St Joseph
's School" so it is something to be careful of.