AIBU to take eldest out of school for the day

[StartofSomethingNew]

I'm really struggling with my relationship with my 7 year old DD since I have had a baby.
For context, before the baby arrived we were very close, probably intensified by the fact we have no support around us (DP works all hours and family don't live locally). However, since the baby has arrived DD naturally gets less attention (a lot less). She has never been demanding of attention before, has lots of friends for play dates and will take herself off to play on her own.
Since the baby has arrived I feel like she is doing too much of playing on her own (not through her own choice) and whenever she asks for me I'm always too busy dealing with the baby (or that's how it feels - and she does get upset about this - she will take herself off to cry (quietly) then try and pretend she is crying about something else - e.g. "I just accidentally bit my tongue").
She is at school Monday-Friday, has an after school activity 2 nights a week and has things on on Saturday and Sunday - all her choice of things (plus the party/playdate invites she gets).
By the time I've picked her up from school, sorted her and the baby's food and bath, plus her reading books and homework, I feel like I have barely seen her.
I'm going back to full time work soon (no option for reduced hours) and it's panicking me. I really want to do something special, just me and her...see a show, maybe afternoon tea, that sort of thing.
The only way I could realistically do it would be whilst my baby has settling in sessions at nursery before I go back to work, so I'd have to take DD out of school for the day/half day. AIBU to do that?

I did just that, OP and I I highly recommend it.

I'd never had even an hour alone with DS1 since DS two arrived. (husband travels abroad a lot, is not very hands on with the children and I have no family nearby). My only one-to-one time with him was/is always doing homework or practice papers for entrance exams etc.

When DS2 started pre reception and was settled in, I took DS1 (6 years old at the time) out for the day. He had no idea, it was a surprise and his little face lit up . I took him to the British museum where he happily geeked out on Egyptian mummies, we went for a nice lunch and talked and laughed and explored, something we hadn't been able to do in 3 and 1/2 years. It was almost like we were rediscovering each other! I felt so sad that I hadn't been able to do something like this sooner. He'd been craving my attention for all those years and to see his little face so happy, it melted my heart. I plan to do it again soon .

Enjoy your day out with your little one

The other thing it might be worth looking at is homestart. Theyre for any family with a child under 5 , and can tailor some support (free!) To yoir family. So it may just be an extra pair of hands for 2 hours a week so you can do something with your eldest or for afterschool so she has some attention too.

Her activities are things she has chosen to do

She's 7 and isn't old enough to judge how many activities are worth doing. As her parent you can explain that it would be good to drop one for the sake of family time.