How should I respect the position of my stepchildren's own mother?

Respect their mother wholeheartedly, because her place in the children's hearts is not yours to take, nor do you need to. Never criticise her in front of the children or compete to be the ‘better mother’. When the children talk about their mother, listen calmly and avoid a sour face. If circumstances allow, help the children remember their mother's important days, such as making a card or calling her. This generosity teaches the children that love need not be shared with guilt. By respecting their mother, you actually win the child's own heart. Also keep good relations between the two homes. See children in polygyny.