Answer:
The cafe owner, as a mentor who is providing her with valuable information about the food service industry.
Step-by-step explanation:
A very basic sentence fragment is missing either a sentence or a verb, as both are required to form a basic sentence.
In this case, "The cafe owner, as a mentor who is providing her with valuable information about the food service industry," is a sentence fragment. You may be thinking that the cafe owner provides her with valuable information, but the comma and the word "as" denotes that this is describing the cafe owner, like an adjective, NOT a verb.