Oh OP...I'm not even going to go there with the whole 'mum' thing. I think we all probably know what you mean but how you've worded it will definitely ruffle some feathers.
Anyway...to the issue...I feel that perhaps as you've aged & moved on from the messy hands on phase of motherhood it sound like you've lost your way with your own style somewhat?
I don't think you should let notions of 'shouldn't' guide you in decisions on what to wear.
The first thing is to have a think about what sort of 'look' you like & then start browsing on various brand websites to see how they've styled things.
I'm mid 50s & I am dressing as well, if not better, than i ever have. My dc are young adults / late teens. I have the income & time now to focus on myself more..
Last year I lost just over 2 stone & that's made a world of difference to me & my confidence
I'm tall & I know what styles I like & what works for me
.
I think it might be worth having a look at some brands like
Sezane
Ba&sh
Maje
Claudie Pierlot
Wyse
Me+em
Sandro
Essential Antwerp
These will give you some ideas to start thinking about . And once you know what you would like you can watch out for yhen in the sales or on vinted etc
Make sure you have a good coat that makes you feel great & a selection of excellent shoes that cater for all occasions & that go with the outfits you like. I'm building mine up to include trainers, loafers, laced flat shoes (dr martens style but nicer), heeled ankle boots & flat knee high boots. Couple of pairs of birkenstocks for summer.
I like lovely shoes & have bought from Toast, Plumo, ba&sh & me+em
I also have 5 or 6 nice leather bags