About the invitation letter. Does it matter what you do in china

Hello my name is Christina, I live in china for two years now. My friend is going to visit me in china. is it possible to write an invitation letter for my friends a tourist visa, even though i am 18 and i have a visa based on schooling, since i go to high school,, well my parents could write it as well but we are kind of running out of time and my dad that he has a business visa might not be able to send the invitation letter since he is on a business trip...
Would that be possible?