This patient support community is for discussions relating to step parenting, anger, behavioral issues, chores, communication, discipline, ex- spouses, family gatherings and meetings, family decisions, frustration, fun activities, grandparents and relatives, guilt, rules, stress, and time issues.
The unfortunate thing is there really isn't an answer to your question. You can't talk to a five year old and make them understand this grown up stuff.
The bimbo that needs talking to is the mother and that won't work. It sounds like she's too selfish to think of anyone but herself.
good luck.
Just stay calm on your end and do not engage the mother if possible. Just tell the girl that you know that you are not her mother, but that you are always there for her if she needs anything--and that you do like her as a step-daughter.
Little ones can understand that.
She might think that because her mother doesn't like you that you do not like her. Five year olds have linear thinking about most things.
The BM is way out of line, don't be afraid to stand for your court ordered rights with the child. Also, it might help to get a child counselot involved to sort out the childs fears, so that she will realize that she does not have to get caught up in guilt and fear for wanting to spend time with her father.