Many books by Abigail Reynolds are available in translation. Here is a partial list of them:

French:

Avec ou sans Mr Darcy? (What Would Mr. Darcy Do?)
La conquête de Mr Darcy (To Conquer Mr. Darcy)
Elizabeth Darcy (Mr. Fitzwilliam Darcy: The Last Man in the World)

German:

Mr. Darcys feine Verwandtschaft (Mr. Darcy’s Noble Connections)
Allein mit Mr. Darcy (Alone with Mr. Darcy)
Coming Soon: The Darcys of Derbyshire
Coming Soon: By Force of Instinct

Italian:

La Lettera di Mr. Darcy (Mr. Darcy’s Letter)
I Parenti Nobili di Mr. Darcy (Mr. Darcy’s Noble Connections)
Coming Soon: Mr. Darcy’s Refuge
Coming Soon: By Force of Instinct
Coming Soon: Alone with Mr. Darcy

Portuguese:

O Refúgio do Sr. Darcy (Mr. Darcy’s Refuge)

Spanish:

Los Ilustres Vínculos del Sr. Darcy (Mr. Darcy’s Noble Connections)
El Refugio De Darcy (Mr. Darcy’s Refuge)
A Solas con el Sr. Darcy (Alone with Mr. Darcy)
Por la Fuerza del Instinto (By Force of Instinct)
Coming Soon: The Darcys of Derbyshire