hey you have your reason's, my husband and I avoid his sister for 2 yrs now, she lives in the same town and we tell people why we avoid her and once they have a reason they don't bother to ask anymore.

As for his sister we just tell her like it is, we can't be around her at this time we tell her she has to straiten out herself before she can be around us or our son, honesty I found is what worked for us....she tried phoning us or coming around and we either pretended we weren't home or told her we were busy but she also knew why and eventually she got the picture, you definitly cannot choose your family but it's your life and you do what fits yourself.