This is made by my husband's oversized t-shirt. I just cut the shirt and stared at it, then this bolero idea came up on my mind. It is very comfortable and yes, we can wash it cuz it's t shirt! Try make one for yourself, and if you use your t shirt, you can make one for your daughter!
Cut the dot line. Make sure it's straight.
Now you cut the round fabric to 2 pieces and make 2 small tubes. (this is going to be sleeves.)
Cut the dot line of shirt, then sew them inside.
Now you sew the red dot and pull the thread to make the circumference in same as sleeve.
Saw the sleeves together.
Now you can wear it!
Sorry for my poor drawing and English description...