Even I used to wonder about Anandi and her connection with mud.
The very first episode of Balika vadhu had Anandi rescuing her honewale sasurjee who had mud splashed on him and after rescuing her sasurjee she herself fell into it got nice facepack with mud
Again she rescued her honewale sasurji this time it is Alok Shekhar from similar situation and got a mud facepack
At that time it felt to me that were telling the sasural 1 and sasural 2 that she is rooted to the ground and she is like the soil and whatever you sow in that soil/ground she will return them in 100 folds.
Same thing with Shiv too.
To bring up the issue of showing kindness to strangers. Her readiness to help people and that she doesn't mind dirtying her hands to help people.
There are some thoughts on Anandi and her connection in mud in this thread if you are interested.
http://www.india-forums.com/forum_posts.asp?TID=3142086