well going to the bedroom when u visit them is not a problem as she might have thought to give u the chance to be with ur dad alone.
but now that ur dad is sick shes on his side all the time and not giving u chance to be with him alone, in my opinion its because of her fear that u gonna ask ur dad for his wealth to be shared to u. SELFISH?
fight for ur love to ur dad, be there for him. make every moment memorable for him.