My PI expects me to help with college essay for her niece while I am struggling to survive on stipend

I am in my third year and currently living on a miserable stipend that barely covers rent, let alone groceries in this city. Out of nowhere during our lab sync, my PI brought up her niece who is applying to schools this cycle and asked if I could give her some college essay help over the weekend. She literally said that since I passed my comps I must have spare time to think about what should i write my college essay about and guide the kid through it.

I was too stunned to say no directly, so now I am sitting here looking at high school prompts instead of running my samples for my own publication deadline. Part of me wants to just link them to a decent scholarship essay writing service or professional admission essay writing help so I can get back to my actual research without failing my degree. Is this kind of boundary crossing normal in academia or am I just being taken advantage of?