to expect my dd 14 to act a little more mature and help out with newborn

That sounds incredibly self-absorbed! As a pp said, sooner or later kids need to cone to the realisation that the world doesn’t revolve around them.

Your baby is only a week old and your husband has gone back to work already? Leaving you with two primary-age children and a young teenager who can't even leave the house on her own. Why was that the plan?? Did he (also) assume his eldest daughter would cover for him so he could work?

If your DD was confidently going to the supermarket alone before new baby arrived and she wasn't busy then of course she should go.
But if she was too anxious before the baby was born there's no way the anxiety is going to disappear and she's going to be confident and independent as if by magic.
Go to a small shop ask her to buy some milk whilst you wait outside, small steps, show her how self check outs work, talk through what happens if there is an issue. Only expect her to get a few items at a time. Perhaps run through a script about what to say/ask for.
Your husband can grab a few bits on way home from work, supermarket delivery for the rest. Stock up on maternity pads, nappies anything essential or that a teen may feel awkward about buying.

You are probably exhausted and hormonal but you need to make time for all your kids, teenage years are hard and having a baby sibling is a big change and might involve sacrifices on her part, room sharing, missing out on activities or just you and her dad's time and attention etc
You should expect your teen to pass you something, make you a drink, put their own stuff away and perhaps a regular chore like unloading the dishwasher but they aren't a co parent or a housekeeper.

Teenage years can be challenging and they often need just as much parental support if not more than when they were younger, make sure there is nothing going under the radar as it's a tricky time and easy to be distracted and miss something.

I keep going back and forth on if you're for real OP.

Yeah, sometimes you do have to just go for it. But maybe not right at the moment your world has drastically changed. Surely you can't be so emotionally stunted as to not see any of this?

She'll be jealous and upset. Sorry if it's not what you want to hear but a lot of teenagers would have feelings of resentment, like the parents are starting over, replacing your child hood experiences, knowing they'll not be priority anymore, feelings of grief for the parent/ child dynamic that will now have to change. I remember my friend when we were 14 found out her mum was pregnant, she sobbed and was really subdued and challenging at home for quite a while. She eventually got over it and had an excellent relationship with her mum and little sister and now wouldnt change it for the world, but she went through the motions before getting there.

You have to teach her, do things with her; not expect her that all of a sudden she is older she will know what to do, do it without being asked.

I would rather my 13DD will not go to the shops alone.

She does her laundry, homework, help with groceries shopping with us and unpacking the shopping, unpack dishwasher, take rubbish out, water the plants, cook with us sometimes, set table. We have a cleaner so luckily they don’t have to clean, otherwise they will also have to clean.

DD17 cooks and goes to the shops alone. Plus same tasks as younger.

I was 15 when my mum had twins - I used to help her when my dad was away for work. It's not unreasonable to ask her to go to the shop for you, or to pass you something, if you're stuck on the sofa feeding. Don't let people on here make you think that you have to do everything baby related by yourself - families are supposed to muck in and help and support each other. It's not a terrible thing to want a bit of help from your teen - how else do they learn to care and empathise and become functioning adults?

That thing said, I think she's feeling a bit left out and jealous though - 15 is still a kid, the teenage years are full of insecurity and clearly she's not coping with the new baby. I think what she needs from you is not being old to grow up (she already feels usurped). She needs your time and attention, conversation and interest in her life to be shown by you. The rest will come in time. She needs yo be reassured you still love her.

You seem to be missing the point.

Why haven’t you discussed how SHE feels? You seem completely wrapped up in how you feel, what you expect, what you want. Even when someone asked why you haven’t discussed the baby, it didn’t seem to occur to you that she would have her own thoughts and feelings on it, you were only considered that she would be bored hearing about yours.

14...she's 2 years off being able to join the army!

She's not a little kid and she's more than capable of doing chores!

Did you prepare her? Show her what to do at the supermarket? She's only 15.

She’s 14 though.

A 14 year old should only be responsible for cleaning up after themselves and keeping their spaces/rooms tidy.

Shopping/childcare and anything more than a few chores is batshit. Let kids be kids.

suspect it could be because a lot of their interactions are online, rather than face to face, so they simply haven't had the practice that we would have had at their age.

I suspect there’s lots of interactions we don’t have these days that would have been more common 20-30 years ago. Particularly if all your shopping is done at larger supermarkets where you can manage you shop without talking to anyone. Largely suspect that adults these days are much less likely to talk to children while out and about these days so children are far less likely to have experience of talking to strangers.

You got your answer there. Why didn’t she do any shores before? And now baby is here she suddenly has to do and learn what she has not done for 14years.

Are the other 2 siblings older or younger?

You have to wait for the staff member on the one till that is dealing with 100s of evri parcels to come across to deal with you. Or queue behind 25+ people to have her serve you from the outset. It’s between ridiculous and I pay the inflated prices at the local convenience store to avoid it

I don’t think that asking a 14 yo to go to the supermarket occasionally, or to bring you something if she’s up are unreasonable even if no newborn in the picture. If you’re bfing, it’s not unreasonable to ask anyone who’s in the house (bar a very small child/ someone elderly etc) to bring things you need.

Is the problem perhaps the fact you’re drawing too much distinction between her and your next child, the 9 yo. At 9 I’d expect a couple of chores other than just keeping the room tidy, and some ad hoc help. My 10 yo is in charge of taking the recycling out, but that’s mainly because he has ADHD so needed a job that’s quite self contained - I appreciate that’s quite an easy job for a 10 yo!

She's not the parent. Yabu.

Your 14yo sounds very anxious... I'm the oldest of 5 children and as the oldest your problems can sometimes be overlooked.

You are not UR to hope for a bit of compassion from a 14 yr old.

How do they sell fags and beer, then?

There's going to be a human around for those.

Yes, most children her age don't mind shopping in a supermarket or local shop. You've not explained beforehand that you might like help, or about anything that she finds "disgusting". It's hardly her fault.

And just to comment on that. It’s not treating them like a 5 yo. On what planet would anyone expect a 5yo to shop unaided?

Its treating them in an age appropriate way.

@the3e7s What was your life like growing up? I don’t want to pry and you don’t have to answer but it maybe feels like you had an unhealthy family dynamic?

So it was ok for you to be too exhausted to go to the shop. But not her?

Because she has just given birth and is breastfeeding without any support, presumably. Use your common sense ffs.