The former Toby Edmonds-trained flyer Houtzen had her first foal, a colt by Curlin, at Stonestreet Farm, Kentucky.
A Group III winning daughter of I Am Invincible, Houtzen claimed the Magic Millions 2YO Classic in 2017.
The winner of seven of her 19 starts and over $2million, Houtzen was initially bought for $105,000 by her trainer, out of the Yarraman Park draft, at the 2016 Magic Millions Yearling Sale.
The career of Houtzen came to a close when finishing midfield behind Blue Point in the 2019 Group 1 King Stand Stakes at Royal Ascot.
Consigned to the Keeneland November Breeding Stock Sale last year, Houtzen was purchased by Stonestreet Holdings for US$1.5million when carrying her Curlin colt.