A:TN G-
It sounds as if all the decisions have been made. When I read the question, all sorts of red flags went up.
- What are the the issues involved in the incompatibility?
- Is your niece willing to accept you as an authority figure and obey your rules.
- Is your sister willing to continue financial support?
- Will you sister support any and all decisions that you make an the custodial parent of this child?
- Who is responsible for the child's health insurance?
- Does your niece have any alcohol or drug issues?
- Is your niece sexually active?
I do not expect you to post answers to all these. I am just saying that you need to go into this with you eyes open and potential problems dealt with.
JayR