It is probably too late for you to make a timely disclaimer of your share--you need to look up NY law on point--but usually one must do so somewhat timely in context of decedants passing--say 180 day or whatever.
So lets say you get a 1/5 ahare of Blackacre. You own an undivided share. Whats the fight all about?--don't let noise get better of you!
If you really want to motivate the Sisters to buy out your share , tell them you intent to lease out your interest to Henry XX, the somewaht unbathed but generally well behaved town drunk or one of his buddies for $1 a month.
If Blackacre is worth $200,000 then the 4/5 owners would be wise to buy you out promptly.