She often gets up at 9:00am.
I always drink coffee in the morning, but my sister doesn't like coffee at all.
Sentence 1
The main verb is "gets up", which is third person singular. Who gets up? ="she" is a pronoun used as a subject, and it is third person singular. The subject and verb in this sentence agree.
Sentence 2
The first predicate is "drink",which is first person singular. Who drink? = "I" is a pronoun used as a subject, and it is first person singular
The second predicate is "doesn’t like",which is third person singular. Who doesn’t like? = "sister" is noun used as a subject, and it is third person singular