She’s as beautiful on the inside as she is on the outside” is that ok?

Supercilious and obnoxious. Many congrats

What is the obsession with social fucking media by anyone over 17???

It sounds perfect and from the heart. It’s what I would put about mine. You can still be lefty, woke, considerate, feminist and post a gushing braggy post about your daughter on her 18th, I would be too and I do every year. No criticism here op, make it as gushing as your love for her. Everyone deserves their parents praise in all areas xxx

This trend of writing the most unique message bigging up a child on their birthday is so painfully embarrassing. The child doesn't care what their mum puts on social media. The poster's friends don't care. Nobody cares.
If you didn't post a message, no one would notice, and if they did then you need to get more of a life off social media.

OP, it's fine, it's an absolutely standard thing to say and in the real world noone will bat an eyelid. I have seen countless moms put this and other similar things for their kids' birthdays.

There is absolutely nothing "cringe" about it - in fact it's such a standard thing to say about your child that I doubt anyone will particularly even register the words.

I'm really surprised you needed MN to validate this message - sure if you spend any time at all on SM you must realise it's a really standard thing to do/say.

Also surprised you thought MN was a good place to ask about SM, where everyone pretends it's a bit tacky and that they are slightly above it (which is ironic in the extreme, when you think about what MN actually is - not a form os SM as such but certainly not a million miles away from one).

And especially that you asked in AIBU, which people think gives them a license to attempt to hurt and humiliated you, however innocous your query. ....

Stop going on about how stunning she is. You've put 2 posts about her being stunning. Whoop de whoo.
It means nothing.
Why are you wanting to make a declaration on SM about her beauty?
You sound so boastful and like you're showing her off to everyone.
"LOOK EVERYONE ON SM! MY DD IS NOT ONLY VISIBLY BEAUTIFUL TO LOOK AT, SHE'S ALSO BEAUTIFUL AS A PERSON TOO! ISN'T SHE AMAAAAAAZING! AREN'T I AMAAAAZING TOO!!!"
Man alive.
So showy.
Just say it to her 1-1 in a private moment. Write it in a personal card for only her to read.
Don't teach your DD about living life through the lens of SM and don't teach her about celebrating girls for being beautiful on SM.
Teach her about privacy. Teach her about the joy of personal moments together. Teach her about real moments in real life having so much more meaning than SM.
Teach her about the fakeness of SM and the vanity of it all.
So many wrong messages you're sending her on so many levels here.
Bad parenting.

I’d cringe if my mum wrote that when I was 18. I wasn’t brought up with SM though (thankfully) so what do I know 🤷‍♀️

I would say something like Happy 18th Birthday to my amazing brilliant clever daughter! I could not be more proud of you ❤️

it’s fine to be a bit soppy!

It’s her 18 th birthday. A really special day. She doesn’t need compliments.

Shocking!!!

That phrase always makes me cringe. I imagine some kind of surgical procedure.

Beautiful inside and out is such a cliche that it's lost any meaning. I would say how you proud you are of her for her achievements and kindness. Presumably you will post photos, so don't need to say anything about her looks at all.

Seems like the priority here is to do something you feel needs doing publicly, and get it right rather than say something you'd genuinely want to say to her (which you can do privately) so personally I'd have a look at what other parents in her friend circle say and go with a similar tone. Because what's 'right' rather than 'cringe' varies from group to group.

Everyone uses this phrase, so it's become a bit meaningless, it's as if people can't be bothered to list the attributes that the person genuinely has .

I believe sentimentality and tenderness should be saved for the person, in person. Not displayed on SM for clicks..
What a narcissistic world.

Why put anything on SM? I thought younger people were pulling back on putting their lives on SM - I know my teens and their friends have wised-up and don’t want their photos or identifiers on any platforms.
So yes, agree with PPs - it is very cringe and performative.

I think the slightly shorter ‘beautiful inside and out’ sounds a bit better as part of a longer list of attributes. I get the not focusing on looks thing but I think it can swing too far the other way if your own mother can’t even tell you you’re beautiful!
I’m not a big Facebook user but think it’s absolutely fine to write a post like this - 18 is a big milestone.If you can’t get a bit sentimental as your child becomes an adult then when can you?! It also doesn’t stop OP from writing a card or letter too.

Bullshit. I love celebrating my own and my DCs’ bdays but hate the gushing SM posts -save it for the bday card - it’s only the recipient who wants to hear they’re wonderful!

Yes! Otherwise it’s all for show and look at meeee

Yep. Just go to the next room and wish her.
My kids would die of embarassment if I posted anything on SM!

I can’t think of anything more cringe, sorry. I would maybe put a couple of photos with ‘happy 18th to my lovely dd’. Your giving your dd a card, presents, will see them on the day, etc? I often don’t see my DCs on their bdays cos of uni terms but we call/Facetime etc - send cards/presents (although thanks to moonpig my DS never got his 21st card, still gutted about that).

You need to ask? Her friends will find it hilarious and she’ll be embarrassed! First rule don’t embarrass your teenage children!

Happy 18th to my amazing daughter! Watching you grow into such a kind, determined, and thoughtful young woman has been the greatest joy. You face challenges with courage, lead with compassion, and never stop striving to make a difference. I’m so proud of the person you’ve become and all that lies ahead. 💛

Just an example

I wouldn’t mention her looks because it’s best not to put value there. Focus on her other attributes as these are the things that will carry her through life.

“I’m so proud of the young man/woman you’ve grown into” is something I see a lot on SM.

I was thinking about this phrase yesterday and decided I didn’t think it was ok! I think you would only say it about a woman / girl and it’s not a healthy message. I’d just say something like ‘happy birthday to my wonderful daughter!’ - that’s enough. No need to heap pressure.