Am I being over sensitive ?

Ask your partner to deal with her, don't let her be your problem. There is absolutely no reason your partner can't interface with his mum.

I agree, don't JADE.

I also agree to stock replies -- "Thanks for offering" "Interesting" "No thank you" (hold your ground and give nothing)

Good advice from VioletSky, justamom.
I wouldn’t let her see she has upset you. Show her you’re tough, by ignoring her.
#6 is positively creepy. I wonder how your partner feels about that?

She sounds exactly like my (now dead so not the same one) ex MIL. A bully. Always knowing best and wanting to be in charge. I don’t think you’ll change her if mine was anything to go by so you need to get your partner on your side and put up a united front. Do things your way and try as hard as you can not to take it personally because I reckon she’d be the same with whichever girl her son got together with. I’m sensitive too and I know how it hurts but stay determined to look after your babies your way, with love. Like my former MIL, it doesn’t sound as if yours is nearly such a loving person as you are. Babies need to be cuddled and not made to stand for long periods when there’s another way, don’t they? Your confidence that you’re doing the right thing will grow, I promise. The proof of that will be your happy children brought up your way, with love.?

Next comment that stings, say quietly to her, can we please talk on our own, tell her how upset at her criticism, you feel upset when she does it and could she stop, it’s up to her then, she needs to change her attitude, you can’t be undermined as your children grow, I’m afraid if she didn’t stop, I would absent myself from her for a while, your husband could take the children to see her, you are pregnant and shouldn’t be having this stress. I love my dil to bits, don’t see her that much, but we love each other, she has never received a critical word from me. My son is her partner and she comes first with him as she should. He would not stand for me talking down to her, but I wouldn’t to it anyone, how can you get pleasure by ridiculing someone?

You are going to have to master the non reply

"thank you for sharing"

"I will think about that"

"that's an interesting idea"

Then just carry on as you are. The more you JADE, justfy, argue, defend and explain, the further she will push.. So don't do it. Let it all roll off you.

She may turn her non helpful remarks on your partner if she can't get at you and he may then realise what she has been putting you through

Some GMs want to be involved and give advice. They really shouldn't!
They are your children and you follow your instincts about how to look after them. Just thank her for the advice but say you will do it in your own way.

Justamom
Time to put the big girl knickers on I’m afraid.
The woman is a bully, but get it into your head that bullies don’t like to be confronted.
I don’t mean in front of a crowd but on your own. Write down what you want to say, practice saying it out loud. No raising of your voice. Just tell her in a cold and calculated way that it’s going to stop.

You are not being over sensitive she sounds awful. Your husband has to back you on important issues and stand up to his mum. He is probably so used to her sarcasm he doesn’t notice.
Next time she makes unwanted comments ask her if she means to be so rude.
She certainly sounds a know it all

Number two problem about the double buggy your partner supported you.

Number three you were right to ignore her and do what you thought best. Well played.

The proper response to number four is for you to say "pish!" to yourself inside your head. The woman is just trying to be one up all the time. One could almost ( almost! ) feel sorry for her insecurity.

Number five. Yup.

Number six is not worth am instant of your attention.

You're doing fine. Just try to ignore her a bit more while smiling sweetly and thinking Oh for goodness sake! in your head.

I seem to have missed no.1

YANBU - she sounds a nightmare! When she tries to give you childcare advice, I would just say that things are done differently now, each generation has their own way of doing things. She sounds as though she is a little jealous of you, I would just ignore her personal comments and do what I did and smile sweetly (and make a mental note of how not to treat any future DIL that you may have!) ☺

Oh Dear I do see what you me but sadly some in laws do get on your nerves. To be frank I cant see her changing and what I would suggest is make sure you and your partner have a united front and stand up to her but not at the cost of all falling out. I think you are going to have to turn a deaf ear to some of this. She sounds like my other was - drove me crazy so I know what you mean. Best wishes.