i do realize that this is/would have been nekama. i got over my pain & am ready to offer sheva brochas.
No, you haven’t gotten over you pain. One does not get over pain by realizing that it is nekama.
You should do it because you want to have a relationship with your sister even if she hurt you.
Then, you should think back and rationalize from her perspective why she may not have made sheva brachos even though she does love you and care about you. And if you can’t get past it, you should ask her (in a few months, not now).