Babysitting issue, what should I do?

I babysit this 18 month old little girl varied days of the week. I have been watching her 3 weeks now. Every time her parents drop her off, she cries for a couple of minutes. After they leave, she is very quiet. Her mom is very concerned about this and hints like there is something I am doing wrong. I have to pull her from her mom every morning. I immediately distract the child with her cup every morning. She cries for a few minutes and then I feed her breakfast, sing songs with her, read books to her, play outside with her every day. She speaks only a few words like mama and dada. The rest is baby talk. She whines under her breath all day. I am also working on potty training her. She doesn't ask. I just put her on it based on a schedule. I also braid her hair once a week. She is just beginning to eat here. She is very picky. Only fruits and vegetables and maybe some Cheerios for breakfast. I am concerned about her not eating. I am also concerned about her speech and withdrawal from me. I try to play games, read, and just be plain old silly for her, but to no avail. She doesn't want to play with me. She holds food in her mouth and then spits it out any where she is standing. Her mom keeps on questioning me about what she does, eats, and why she is crying every morning and so happy to see her every evening. I don't know why she is acting this way. I am doing everything I can to make her feel welcome. She just doesn't seem to like me much. She whispers when she talks to me. Am I doing something wrong? I have been researching on the net about separation anxiety, but it is like the mom and child both suffer from it. What should I do? Should I recommend a more social daycare for her? I only charge mom $85 a week. Now she seems to question everything I am doing as if I am mistreating this little one.