Holy Cow! It is the most crushing feeling to hear your little one cry when you leave the room, but it happens right around this age. According to my son's doc, at this age babies start to associate things that they've heard, seen and smelled with the important people that are always there, like Mommy and Daddy. With limited ability to see everything around (head/shoulder control) them because they don't know that if something is out of sight it still exists, there natural fear of being seperated from the ever important Mommy can be scary. My son would cry and cry and fuss if I even left his sight for a second...it got better when we kept one consistent person watching him whenever I had to do something and we started small. Like 30 minutes to take a shower and wash my hair and having Grandma as the constant caregiver. Then, we moved up to leaving for an hour to get a hair cut. Pretty soon, it subsided, but we still now at age 2 have some issues occasinally with him fussing if I leave and he's not ready for me to go to work.
I think the important thing is to explain things to your little girl, she may be young but they comprehend so much at any stage. I agree, make it quick and don't hesitate. Talk to your caregiver about working on a routine to get her distracted when you leave, toys or books or something that can always be her comforting object when you aren't around. For my son, it was a dinosaur my sister bought for him...he out grew it by age one.
Good luck!
Deanna