OP...I'm sorry you are going through this. Being a new mama can make you feel a bit touchy and sensitive to criticism...we've all been there. (((hugs))) I agree with everything AdalinesMama said, a thousand times over. Also, I think Spring Lily is dead on.
Look, you are this kids mama. You are making good choices for her and you need to let the bullcrap from your mom and sister go. It is nothing. Seriously, really consider it. With everything going on in the world, all the kids out there with no one to care about them, all ways in which your mother and sister could be enriching the world or making positive changes in their own lives...all they can find the time for is sitting around picking at the choices of an extremely hands on mama like you? Please. It's just immature. They are being a couple of negative nelly busybodies with nothing better to do than talk about you and what you have going on. Please don't sit and waste your time playing this game with them. There is way too much other stuff you could be doing...like sleeping, playing with your kid or remembering what an awesome mom and person you are. Oo, or eating chocolate. Mmm.
I say this as gently as I can.....you just need to let go of needing validation and niceties from them. Honestly, they are probably picking on you because you are choosing to do things differently than they did and because the things you are doing involve MORE from you as a mother then the choices they made/make, they are reacting to your choices as if you believe your choices to be better SPECIFICALLY than THEIR choices. It sucks that you can't get support from them....but it doesn't suck *that* bad. The easiest way to stop caring about their lack of support, is to stop needing their support. If you are not going to get it (and it looks like, for the time being, you are not) then you just need to let go of that. It would be really nice to have it...but you can't MAKE them support you....all you can do is either a) waste your time pining for it and feeling bad or, b) not. I would choose to not do that. There are so many places you can go to be around people who get what you are doing and are doing the same things....in those places you can trade notes, support each other through the hard parts, etc. and really feel good about being involved in a community of people who understand what you are trying to accomplish with your parenting.
Yours is a story as old as time. Hens clucking in your ear about this and that. Let it go. You have a healthy kid and the luxury of living in a world where you have time to seek out and practice different ways of raising your child according to your own wishes and values and best hope for her. That's a pretty awesome blessing. I'm not trying to be dismissive of the fact that their behavior is hurtful....I'm trying to remind you that you really can't change their behavior....but you have a whole WORLD of power to change your OWN. The way they behave isn't what makes you feel "bad" or "good" - the way you CHOOSE to see their words and react to them is what makes a lasting feeling inside of you.
If you want to feel good in your interactions with your mother and sister...that's going to have to be on you...because, apparently, they don't have the good sense to get over your different style and just be happy for another happy, well cared for baby in the family. It's time for you to shift your reactions and really, more importantly, your expectations...so that you can be around them, love them, and not feel hurt by their silliness.
The newness of motherhood wears off very quickly for most mamas and it feels much less cutting and personal when people pick on your choices. Until such time as that shift should occur within you, I would shift my expectations, see how petty and small they are being....and kindly invite people who are being truly offensive to shut their mouths and leave you alone until they feel like being productive, positive people in your life. Seriously....when someone is behaving like a careelss child with your feelings...treat them like one. With a perfectly straight face and a completely even tone, say "Shame on you, is that really how you treat someone who is obviously doing her best and who never has said a single negative word about YOUR parenting choices?" - and then just walk away and busy yourself. Don't get mad....just turn a mirror to their behavior. THere is nothing here to be mad about. They are wasting their time, living in a negative stew of smug self righteousness and refusing to see the beauty in your love for your child.
The way I see it...they are losing. You can choose to lose with them...or you can lift yourself above it and win all day with your beautiful kid and your perfect love. GL.