How do I handle a greedy sister who I'm the other 1/2 of an estate?

I'm going thru an estate from my mom who died w/no will. my sister and myself are sole heirs. my sister was just removed as adm.. we now have a non-partial adm.. my sister wants it all. I'm playing mr. nice guy who just wants my 50 %. I know this isn't much info but anybody that has had a similar issue, you're exp. would be helpful.