Confused. Does anyone know what this blue stuff is???

Shes produced urates/urine about 5 times now... Just the one had the blue in it.

Shes a ball I picked up from a breeder roughly 10 or so days ago. Fed three times on 3 small rats. Hasnt defecated yet. Was she just really thin when I got her? I've attached pictures of her from today... She isnt very round yet. Do you think shes constipated or just has more room to eat still?