Emotion Awareness:

 K&1 My Many Colored Days by Dr. Seuss

 K&1 In My Heart by Jo Witek

 2-4 In My Heart by Jo Witek

Separation Anxiety/Grief:

K-4 My Invisible String

Mindfulness:

K-4 I Am Peace

Gratitude: 

1-4 Those Shoes by Maribeth Boelts