moodiness

Jennifer
My sweet baby is one month old. Everything is going great with baby boy. Only thing that has changed with me is that I've been super critical and moody towards my mother in law ever since he was born. I think it started off because I felt like she was questioning everything I was doing with him. Once I brought it up to hubby he has said something to her about it two or three times. She seems some better about it but I still catch comments of her telling me that I should probably be doing this or that or I need to make sure I'm watching for this, etc... She said she didn't mean anything by it. She's just really precautious because she has another grandchild to die from sids about 5 years ago. Am I being crazy/unrealistic about this or is it normal to feel this way? Anyone else have any similar type feelings?