Here's a possible interpretation and correction:
Possible Meaning:
It might be trying to say: "Her grandmother is at her house cooking for you today."
Corrected Sentence:
A more correct way to say this in Spanish would be:
* "Su abuelita está en su casa cocinando para ti hoy."
Breakdown:
* Su abuelita: Her grandmother
* está en su casa: is at her house
* cocinando: cooking
* para ti: for you
* hoy: today
Let me know if you have any other Spanish phrases you'd like help with!