Make it something to the point, not a novel. Make it about something you've been up to while mom's been in the hospital. She hasn't heard from a lot of her friends in a while.
Also make a note if your apart of Family, CCN, Church, compassionate friends or any group my mom is a part of. if you're not a part of these groups i doesn't matter.
Don't forget to put your name in. I'll read them as they come in so if you think you missed sending her a msg don't worry. i'll get to them as they are added.