hey, I thought my mother would flip out too! Writing a letter is a good idea, especially if she has a tendancy to get overemotional right at the beginging. That way you can give her her space for a while. My mom had a series of emotions, but she’s mostly excited about her first grandchild. Also, it may help to know as much as you can about your options, how you plan on dealing with school, work, and family, ect. So your mom will know that your serious about this and willing to do all it takes to raise a happy, healthy baby! Also, I tried not to bring up how involved she would be or what kind of help or support she would offer, and let her make that decision and come to that herself. She’ll come to terms with it, even if she’s not happy in the begining. I suggest telling her soon, or she may feel left out that other people knew long before her. Best of luck!