Tenant wants to pay for a 6 month lease up front, should I do it

[Lee V.]

A 20 year old college student is wanting to rent my cottage for 6 months because she graduates this year and is planning on moving out of state. Her grandfather will be paying me the full amount up front. She is currently living in an apartment complexes and her grandfather was paying all of her rent there too. The apartment lease is now up so she needs a place to stay for 6 months until she graduates. 

Assuming her current t apartment gives her a good recommendation, and she seems like a good person and clears backround credit check.

Would this be a good idea?