Hello Bryan, it seems to me that you should allow your wife to bring up the baby in the way she is most comfortable with, if your wife tries to use a method she is not familiar with then your baby will most likely suffer. Talk to your mother and ask her to respect your wishes and to support you and your wife in the manner in which you are both accustomed. Acknowledge your mum's expertise but explain also that you do not wish to hurt or upset her. Tell her you hope she will understand and ask her to try and support you and your wife in the way you have chosen to look after her grandaughter. After all you all have the baby's best interest at heart. Take care and good luck.