German mumsnetters, please help with birthday etiquette

[MrsMopple]

Guten morgan! That's about as far as my german goes...

My german great aunt is 90 next week and I want to send her some flowers. What I would like to know is, do I put 'Happy 90th Birthday' on the card, or just 'Happy Birthday'?

(Or rather should that be Herzlich Gluckwunche fur deine geburtstag (spelling all wrong, I know!)

I really don't want to cause offence (I'm already ashamed enough that I never learnt german) and would be grateful for help

90 is special, I'd mention it, she's bound to be proud to be going strong at that age.

I would write: "Herzlichen Gluckwunsch zum 90. (or in words - neunzigsten) Geburtstag"

(I'm not German though)

Thank you ZzzenAgain, I didn't mean to exclude non german MNers, just thought that they would have the best idea of german culture!
I'll copy that phrase out for the card

Personally I wouldn't write out the age on the card. Germans do not make a big fuss about their birthdays, esp. the older generation. If someone is so old, do you think they look forward to their 90th (!!) year? It's a grand old age but still, esp. if it's a lady. Having said that, people are different, you will know her best.

I'd write:

Liebe xxx,

herzlichen Glueckwunsch zum Geburtstag und alles von Herzen Gute wuenschen Dir

Deine xxx und xxx, xxx, xxx

I am German, btw. If that helps

Really? In my experience Germans make a big fuss about their birthdays. I'm German too btw.
My grandmother's and my parents' birthdays were always celebrated in a big way. Especially for the round ones there would be usually a party in a restaurant or in the church hall which started with Kaffee und Kuchen and then went on to dinner. There were about 80 people invited to my grandmother's 90th.
This is normal where I come from. My family isn't the odd one out when it comes to birthdays, not in Unterfranken at least.
I don't think there is a rule about putting the age in or not. Some people do, some don't.

Exactly what I said, people are different.