I sat on a rolling stool in the tiny 8' x 5' pre-surgery room holding her hand as the doctor-in-training took a very long time practicing putting an IV into her arm. We giggled when she had to put the blue paper cap over her hair. I held her hand again as we watched the ultrasound of her femoral artery as they stuck the needle in, rendering the top part of her leg and knee numb and painless.And then I had to let go as they wheeled her away.In so many ways I am having to let go. In a month she turns eighteen and she will have to sign new forms so that doctors will share information with me. I will no longer need to sign forms on her behalf. In August, she will go far away to college.I sit here waiting while she has her knee surgery, hoping she is safe, that things are going smoothly, that nothing goes wrong.Life as a mother is filled with such moments.I will nurse her tonight and make her Spaghetti-Os and help her manage her pain. This year, Mother's Day will be spent mothering a daughter, something that I am going to cherish, since I realize how finite this time is, how few such precious moments I have before I must let go once again.