Rant- overly opinionated sister

i just need to rant and vent. My younger sister is single with no children and can be quite bossy and opinionated. she seems to think she knows what's best for everyone else. She's shaming me for a choice I haven't even made yet. She keeps telling me the line "breast is best" and giving all these stats and crap. I obviously know this, but my attitude is "fed is best". She overheard me talking to my mom and I said something to the effect of if breastfeeding doesn't work I'll have to go to formula. and she barged in reading me the riot act. I told her it doesn't always work for people and I will have to make the best choice for me and my son. She replied "well with that attitude it won't happen." excuse me? I'm just not putting all my eggs in one basket just in case. I see it as if I can breast feed that's awesome and I'll do what I can to make it work and if I can't then I will use formula. I don't want beat myself up. The other day she came over and saw some free samples of formula and freaked out on me. I'm done responding to her. I just can't anymore, it was free! I'm not turning down free anything for baby! I just needed to get this off my chest. anyone else have bossy or opinionated relatives?