Ultimately you are the parent. You can remind them of that gently. I had to do that with my own mother a couple of times in the beginning and she had to respect that. The fact that I already had loads of experience with children did make it easier for me to make her understand that I was making decisions based on some of my first hand experiences. This relaxed her a lot. Family (and friends) will always tell you what to do but you can let them know that you feel confident in your decisions as the parent and that it is their job to support and not interfere with your parenting decisions. You can also let them know that you really appreciate all the love and concern they have for this baby and that you value their place in your child's life. Also that you will want their advice sometimes and you hope that they are willing to be helpful and open minded when you feel you need their input.
For me just saying this directly got us passed that hump early on and it has been no issue since then. Now my mom seriously praises me all the time and goes on an on about what a great mother I am and how my decisions were obviously so spot on because look at what fabulous results we have gotten.

You can still smile, nod, ignore, and laugh later. Luckily my mother in law has 7 kids of her own and had the same parenting style as we do.

But, maybe if it gets out of hand you can have your husband call them and have a very non-confrontational chat with them about how you're raising your child is your choice and even though you both know they really do mean well and will take their words to heart, the decisions are ultimately yours.

It might be easier for him to say it rather than you. I've had to tell my own mom a few things. But, now she knows that what I do with my kids is working for US because she sees it now that my other two kids are much older. The proof is in the pudding. Hopefully they'll see that in a few months and things will be better.

it is tricky in the beginning, but yuni is right : ultimately you and joe are lyra's parents ... do what makes you guys feel good.

a great line my midwife gave me as a reply for those times when someone said, "put her down, or you'll spoil her!" is : milk spoils, babies are loved.

1. Even conservative, mainstream MD's talk about the first three months after birth as the fourth trimester of pregnancy. There are videos and books about this. It might help the in-laws get a more healthy perspective on what your child needs right now. This might only put them on hold for three months, but it is something.

2. You could agree with them somewhat. Tell them, yes, you want to train your baby right now. You want to train her to know that she is loved and nurtured. You want her to know what it feels like to have a healthy happy connection with those that love her...or something like that.