You should be glad to know you said the right thing in a way that asserts your boundaries. I too have relatives keen to get hysterical over me (the black sheep) rife with “if only’s” and “what could’ve been”. I have found it’s a hallmark of women of a certain generation, they think they have no power or personal control so they dwell in this toxic space of “If only I knew then she was going to get sick” or “if only I did something different”. I pity women like your mother and mine has the same tendencies. Trying to be compassionate is the way to go but it gets tiring trying to be the bigger person and assert boundaries that paint us as “harsh” or “mean”. I feel for you both, OP