Sarah's brother could be called..

[IgglePiggle4Tea]

Sorry, we're really struggling! Two syllable surname beginning with a hard D.

Rupert or Jacob .

I’m a Sarah with a brother called Sean 😌

Alexander

Definitely Andrew. It is a classic name like Sarah but has not been overused recently!

Mark

Peter
John
James
Laurence
Luke
Philip
Stephen
Simon
David
Daniel
Robert
Richard

Yes but… Sarah and Andrew? Not a great combo at the moment with all the controversy around Prince Andrew.

Sarah and...

Joshua
Josiah
Asher
Jonah
Noah
Levi
Luke
Isaac
Gabriel
Tobias
Elias
Elijah
Joel
Abel
Jacob

Samuel?

David. I like the alliteration with your D surname.

Agreed, avoid Andrew- with the Prince Andrew scandal it’s not a good choice.

Angus

Matthew
Jared

I immediately thought Matthew. But Sarah is a classic name that I think would go nicely with any similarly classic boy's name. I know a Sarah with a brother called Douglas.