3yo DD insists she's a baby

[SausageSmuggler]

DD is 3.9 and has always enjoyed being the youngest out of her and DS (5). We've never babied her and encourage her to be a 'big girl' in things like going to the toilet and dressing herself, both things she is capable of doing herself.

However, she's really gone to town on insisting she's a baby since DD2 was born in July. I completely understand why she's doing it but it's making it very hard to develop her independence. It started with wanting us to get her dressed, then taking her shoes off, the latest thing is she wants us to wipe her bum after doing a wee.

I really try not to pander to it but she knows when we're on a time limit (like the school run) and is worse then, knowing that I'm more likely to give in to speed her up. Along with the constant defiance, tantrums and hitting its really wearing me down.

I've tried

DD2 managed to press post!
Anyway...
I've tried bribes, threats, telling her why it's much better to be a big girl, rewards, giving her more time. I've run out of ideas! As I say, I understand why she's behaving this way but I have no idea how to manage it!

Could you just play along? I would see it as a scenario she wants to play out and let her do so when you can accommodate it.

DD is the same age and also likes to play at being a baby.
No younger sibs. Even without a baby in the family, there seems to be a lot of feeling around for her place. I don't know about your Dd, mine is very aware about school coming up, so she's dealing with being a big girl at preschool now, but at the same time too small to start school with many friends.

When she wants big girl treats - advent calendar, parties, meals etc - she will have to stop the game. And I put my foot down about some things I can't practically do, like carrying her around. "Sorry babyDD, you're too heavy, you'll have to learn to crawl now!"

To be fair I haven't tried that, mainly because she's the kind of child who, if you give her an inch will take not just one but several miles and I'm worried it'll encourage her to play up to it a lot more.

I have a 4 year old who has regressed a lot since starting school. I just I along with it - it's quicker, easier and meets her (emotional) needs. She's mostly stopped it now at the end of the first term and it's much more noticeable when she's tired.

I would just baby her a bit esp things like wiping as her drive to independent will pick up again - this too shall pass.

That's very usual with a baby around. Find a couple of things only you and her can do. "not the baby because she's not big enough" and indulge her in some things when it seems reasonable.

Dd2 was a buggy refuser from a very young age. When I was pg with ds she suddenly announced "that baby is not going in my buggy". She hadn't voluntarily gone in the buggy for probably about 2.6 years and rarely did. She made a stand once, then decided that actually having the buggy wasn't as good she'd thought and never bothered again.

DS2 did this about the same age, without a baby in the house.

It was really irritating. We sort of half played along, and insisted on him using words when he was doing it too much. He outgrew it after a month or two.