Should I not be angry with my older sister?

They say that I must not get angry with my older sister but I can't help it I know I dissapointed her and make her angry because I get pregnant but I did tell her early so that it won't cause big trouble and then I said sorry but unfortunately at my wedding she did not attend I was hoping that eventhough she's angry with me she would attend my wedding but she did not showed up so I was so sad and dissapointed I just can't help it.. Its my special day but she did not show up. Should I be angry or not?

Should I not be angry with my older sister?
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