If you have convinced her to continue looking into it, that is a great accomplishment. I hope the best for her and her son. And you.
I have been recently thinking about the whole "parenting decision" thing. It seems if I bring up circ, or the possibility of not circing, parents treat it as though I was getting all up in their face and demanding they have to breastfeed and must never give a drop of formula. Or similarly meddling in something that is really their choice as parents. In other words, as parents we really do have the right to choose how to feed, clothe, entertain, carry around, educate, put to sleep, and provide medical care for our children. We can all make different choices there, according to what works for us personally, our families, and what we feel is best for the child.
BUT circumcision is different. Because NO action needs to be taken on a normal healthy baby with regards to surgery, there is NO decision at all to be made, therefore it is NOT a "parental choice."
So, it may be worthwhile to apologize to your sister for meddling in her choices about how to parent her baby. I'm sure you wouldn't mean to "meddle," you probably just felt so happy with what you were doing that you wanted to share how wonderful these methods are. But that you realize it isn't your place to tell her how to feed her baby, or put it to sleep, or any of a number of other things. However, just as you have no right to make her choices for her, she has no right to make her baby's personal choices for him. Circumcision falls outside the realm of "parental decisions" and you hope that after she looks into it, and sees that it is not necessary as well as painful, she will decide to let her son make his own choices about his own body when he is old enough. Just as you have seen the error of your ways and are going to back off and let her make her own choices.
If she can see the parallel, maybe she'll see that circumcision is her son's choice to make and he wouldn't appreciate her meddling in his choice.
sorry that is rambling... kids are up, got to go make breakfast!
Jen