Unfortunately, I think that only time and patience will help this situation. It is good that mom is going to bring her full-time for at least the 2 weeks. I always find that kids who come part time take two or even three times longer to adjust to daycare.
Keep in mind that 2 days is not that long, and although I know that your nerves are wearing thin, it's still pretty early to say "she is not adjusting".
I think that the idea of a baby carrier is a good one, then gradually transitioning her to sitting/playing on her own. Keep the lines of communication with mom and dad open, tell them honestly how she does each day, and what you are doing to help her. Hope to heavens that they really are working with you (letting her self soothe, etc). If at the end of the 2 week period you have seen NO improvement (she will likely still cry, but is it getting better?) then perhaps let mom know that she needs to be in a more one-on-one care environment, for now at least.