What to write
What to write in a birthday card for your sister
A sister has known you your whole life, so skip the generic and make her card as real as she is. A shared memory or in-joke beats any shop-bought line.
Birthday messages for your sister
Happy birthday to the sister who knows all my secrets and loves me anyway. Lucky doesn't cover it.
We've shared a childhood, a thousand arguments and a whole lot of love. Happy birthday, sis.
Happy birthday to my built-in best friend. Here's to another year of being ridiculous together.
No one gets me like you do. Have the best birthday, sis — you more than deserve it.
Happy birthday to my favourite partner in crime. The world's lucky to have you; I'm luckier still.
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Questions
What do you write in a birthday card for your sister?
A sister has known you your whole life, so skip the generic and make her card as real as she is. A shared memory or in-joke beats any shop-bought line. The strongest messages name one specific, true thing about them and say plainly how you feel — keep it short and it lands harder.
How long should a birthday message be?
One to three sentences is plenty. A short, specific line beats a long, generic paragraph — people remember the detail, not the word count.
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