Explain why Mrs. Putnam was so concerned about the condition of her daughter in The Crucible.

Mrs Putnam has a history of problems regarding childbirth and the rearing of her young, as she herself emphatically declares:

Reverend Parris, I have laid seven babies un-baptized in the earth. Believe me, sir, you never saw more hearty babies born, And yet, each would wither in my arms the very night of their birth. I have spoke nothin', but my heart has clamored intimations. And now, this year, my Ruth, my only - I see her turning strange. A secret child she has become this year, and shrivels like a sucking mouth were pullin' on her life too.  And so I thought to send her to your Tituba - 

Her reference to 'intimations' suggests that she believed that there was a wicked force afoot which denied her the privilege of raising children in these instances since they were either stillborn or died during childbirth. It is also apparent that she was deeply concerned about Ruth's condition, for she was 'turning strange.' Ruth was the only child who had survived past childbirth and in her desperation, she turned to Reverend Parris's slave from Barbados, Tituba, to seek help. 

Her later statements emphasize the fact that she believed demonic forces had killed her children.

They were murdered, Mr. Parris! And mark this proof! Mark it! Last night my Ruth were ever so close to their little spirits; I know it, sir. For how else is she struck dumb now except some power of darkness would stop her mouth? It is a marvelous sign, Mr. Parris!

Mrs. Putnam's assertions clearly indicate her ignorance. She could not fathom that there may have been something wrong with her and grasped at whatever she thought was an explanation for her failures. It is patently ironic that she did not seek further divine guidance and help or consulted the doctor, but that she approached Tituba for assistance. The irony lies in the fact that she and her husband later become most vocal in accusing others of witchcraft, whilst she was the one who had sought supernatural assistance from Tituba, who was believed to possess the ability to conjure spirits. 

Since Mrs. Putnam refused to accept responsibility for her children's deaths, it became easy for her to blame others, thus turning attention away from her own guilt in seeking alternative remedies for her problem - an extremely un-Christianlike approach. She insists on blaming sinister forces for her children's deaths even after Rebecca Nurse suggests that she go to God for answers and that she should look to herself for blame.

But I must! You think it God's work you should never lose a child, nor grand-child either, and I bury all but one? There are wheels within wheels in this village, and fires within fires! 

Furthermore, she was indignant about the fact that others were more successful at giving birth and raising children than she had been. She turns against Rebecca Nurse who had successfully given birth to and raised, a number of children. Mrs. Putnam could not understand why her family's greatest opponent and enemy, could be so successful whilst she had been an abject failure. The two families had been involved in a long-standing feud about political power and property and she and her husband despised the Nurses for their success.

Added to that was also the fact that, despite the Putnams and Reverend Parris, the Nurses had no known enemies in the village and were highly respected by all and sundry. This increased the Putnam's animosity to the family and they were, therefore, out to get them and purposefully went about to destroy them. To this purpose, they later accused Rebecca Nurse of witchcraft and of sending out her spirit to prevent the birth of their babies or to stifle them soon after.  

It is therefore not surprising that later, the Putnams use their daughter who had been involved in illicit goings-on with other girls and Tituba in the woods, to point fingers at whoever they wanted to punish or get rid of, such as the unfortunate George Jacobs, who happened to be in dispute with them about land. They had found a method to get rid of their opposition and maliciously used it, claiming many innocent lives and destroying families in the process.