You are Meera. Write a letter to your mother telling her about your hostel life.
Here is a sample informal letter on this topic. You can learn about the format of formal and informal letters here.
Informal letter sample
Room No: 18, Chanakya Hostel
June 6, 2020
My Dearest Mom
I know you are still worried about me and I am writing this letter to put your mind at ease. I am doing absolutely fine here. My roommate Aswathi is also my classmate and I share a very warm friendship with her.
The hostel food is good. Of course, it is not as delicious as the meals you served to me, but it is okay and I have no complaints. Our warden is a kind hearted old woman and takes good care of us all. She reminds me of my grandmother.
I know you miss me a lot. I miss you too. Hopefully, I will be coming home for a couple of days next month.
Lots of Love