DD won't tell me anything about what she's up to

This.

there are ways of communicating. I would often say “going anywhere nice/interesting?” or ask if she’d be back for dinner.

i don’t need who where how long, is it a new boyfriend, ooh are you going shopping, give me a second i’ll come…

i get told when she’ll be in late or staying out, basic manners, but the detail is up to her to share.

It’s useful to read this thread as mine are similar ages.

i guess they are trying to separate from us and it’s a blunt tool. A regular housemate might say ‘I’m off to shops etc’ but they aren’t regular are they? They are trying to forge their independence from us.

I've got my 23 yo back home after graduating and 4 years of uni. He is looking for his proper job at the moment, so currently working part time in a pub.
All we ask him to tell us is which shifts he is working, whether he'll be in for dinner (for shopping reasons) and if he isn't coming home (so we can lock the house properly).

If he is going out he'll either say he is just popping out (so a quick trip), or otherwise when he'll be back for longer outings.
We'll just tell him to have fun, which sometimes leads to him telling us more info as to where he's going, who he's meeting etc, but I don't feel any right to know any of this. He is an adult!

Instead of asking where she's going why not express the hope that she has a nice time? The more you quiz her the more she will try to protect her privacy.

I find this really hurtful. I'm her mum and I care about her. I don't know what I've done to make her not tell me anything

This way of thinking is the issue. You're being overly sensitive and making this all about you. My mum can be like this and I find it exhausting. Your daughter has probably got a boyfriend or is going on dates and doesn't want to share the ins and outs with the family. If you were dating would you want to give a running commentary to your parents? Let her have a private life.

As Lots of others have said, it is not unreasonable for a 25 year old to want to go about her life without sharing every detail. However, I can understand how it must be difficult as a mum to adjust to your child having their own life despite still living with you.

I’ve shared my experience of learning to let go (spoiler- it’s hard!) here:

Yes we exchange pleasantries amd I have no expectations as to how much my dd will tell me at that time.
She had an offer fall through at the last minute which meant she has to leave the city she loved and come back home unexpectedly, so yes a lot of adjusting and acceptance of her situation right now.

I do find it a bit strange that an adult goes out without any word to the other adults about where she is going/what sort of time she'll be back. I wouldn't just walk out of the house and not tell anyone where I was going or refuse to tell them when I got back, very odd behaviour.

I stopped telling my mum things about my life in my 20s because I knew she would end up telling the rest of the family. I asked her to stop, she didn’t, so now she doesn’t get to told anything.

I reckon it’s either she’s in the early stages of a relationship, like others have suggested. Or maybe she’s not up to anything particularly interesting and doesn’t think there’s anything to tell.

Yeah sorry, welcome to having an adult child. Once she moves out you'll know even less. From about 21 my mam had absolutely no idea where I was going, who with and what I was doing of an evening. Because I was becoming an adult and spreading my wings and enjoying having a private life.

I get that you're used to knowing every nuance of your child's life and it's hard that she's not interested in sharing things with you anymore, but that has to end eventually, she has a right to a personal life and you don't have a right to know the details of that anymore. She's not a child, she's a grown woman, you have to let go a bit.

If it's any consolation they often come back after a few years and share things again, once they've gained and lived that independence a bit. My mam and I catch up for a coffee and a chat about what we've been up to once a week or so now, but when I was your daughter's age I guarded my personal life like they were national secrets.

Both of mine tell me a lot about their lives, as I did with my late mum.

It only takes a pleasantry like, "how was work today?" and they can tell you as much or as little as they like!

It's hard when they move away and then move back - mine have done it a few times. Not sure if that's the case here but there's a lot of adjusting on both sides.

I was sharing my experience, which is that there is a basic level of communication going both ways, which is what the thread is about. The OP is unreasonable as her DD is 25 to demand more!

It sounds like she could be seeing someone and if it's early days she probably wants to keep it private for now. She's 25 and doesn't have to tell you where she's going but it's polite if you share a house to let you know if she's staying out overnight. I have adult children at home and they would tell me if they're staying out, as I would tell them. Give your daughter some space and just keep your chats general.

My DD moved away for university. She has come back home for a bit and absolutely hates me asking her anything.

She had a difficult time for half a year with MH. I had to collect her from uni at one point as she was unable to look after herself. It was a scary time and I worried so much about her when she went back to uni.

So when she came home this time I know I was hovering too much, and it made her feel weak and like a child, like I didn't think she was a capable adult.

So I just let her come and go and don't question her. Every few days she comes to me and we have a catch up. She chats and fills me in on everything in her own time.

Op your daughter probably feels like she's not a child anymore and realises she doesn't have to tell you anything.

I certainly don't tell my mum the ins and outs of my life, do you?

Stop asking her so much and let her come to you if and when she's ready.

Stop pushing the issue, she will just withdraw further.

The sooner she moves into her own house and can live her own life the better for everyone.

But that's not what OP is on about
She wants details

I don't need to know that either but I like to know when to expect them home etc.

Her mother knows she's out.

She doesn't need to know where or who etc

I clam up still when my mum asks me too many questions. And I’m 40! My daughter also does. She’s now 10 and slightly better but I used to get nothing out of her about school. And the more I asked the worse it got…. ‘What did you do today: nothing. Who did you play with: nobody. What did you have for lunch: nothing’. Now I just model the behaviour I want and greet them with a really boring work story and the best and worst thing about my lunch (cheese toastie again… this time with mustard).

unless you think there’s a chance she’s in an abusive relationship? Also are you judgemental / disapproving of some lifestyle choices?

I think it's pretty basic courtesy to let whoever you live with know when you're coming and going, so they don't worry? I tell the rest of my household.

Living at home or not, it's none of her mother's business so long as she's not bringing people into the house or disturbing them late at night/early morning!

I've DDs similar ages who pretty much tell me everything, but I don't expect them to. I do think she should tell you her basic movements as a courtesy, eg "I will be home late tonight" but if she wants to keep the details private then that is up to her.

They've moved in and out of the family home for various reasons and when they are not living at home we still speak a lot.

Can you take an interest in her new house and bond over that?

Yes she is an adult and doesn't have to tell you where she is going or what she has been doing.

But you're living in the same house, surely a casual 'what have you been up to today?' conversation happens? Or a 'I'm off out this evening, might not be back till late, see you in the morning'.

How was your communication when she was a teenager? How long has this lack of communication been going on for?

YABU

She’s an adult and doesn’t need to tell you anything.

It’s odd that you think she should.