Christo, I would urge you not to beat yourself up for what you think you shoulda done or shouldn't have done -- something at which I fail at miserably.

If your sister doesn't want to come, perhaps she will make up some last-minute excuse. OTH, if she has agreed, perhaps she has a deep inner longing to be there. Small children can be such a gift from God, perhaps she longs to be in the presence of your child's unsullied innocence.

Even if you are "too agressive" with her in your own opinion (which may be distorted), at least she can have no doubt that you care and are concerned. And I think that is much healthier than her being alone and wondering why no one is holding out a hand to help her and support her.