The first concern is the equalizing of the three sisters – three equal roles? For beginning screenwriters, the recommendation is to focus on one protagonist. Maybe it is the most estranged sister who comes back to find two sisters who have been dealing with mom all along. Or maybe it is the “closest to mom” sister who is now the mediator between mom and the two sisters who fled, who are suddenly in the picture. For me, the latter would be the most interesting because given Alzheimer’s progression, which you can also zoom in on, there’s a phase where some memories are accurate and others are not. The “closes to mom” sister would have to act as the truth-teller and this would lead to a new type of bond – namely, great appreciation for the sister who stayed home. Great appreciation can be as powerful as “happy,” perhaps more so. The big missing component here is the “event.” What leads to this situation? Maybe when somewhat still independent mom changes her will and “closest to mom” finds out and reaches out to the other two to let them know they have been cut out, leading to their very fast appearance. ?Money goals start it all off… How about: “When a mother’s slowly progressing Alzheimer’s leads her to change her will and cut out two estranged daughters, the at-home daughter reaches out to her sisters to device a plan to get them back in the picture for their own benefit and to re-establish a family bond.”