Prince Of Monaco is out of the unraced Rainier (Medaglia d'Oro) and is the first winner among her two runners. Rainier is a half-sister to Laurie's Rocket (Bluegrass Cat), a dual stakes winner, twice Grade 2-placed and now a sire, and to the stakes winner Greeley's Rocket (Mr Greeley).

Second dam Clay's Rocket (American Chance) won four races and was twice stakes-placed. She is a half-sister to Adieu (El Corredor), winner of the Grade 1 Frizette Stakes, to the Grade 3 winners Direct Line (Tiznow) and Rapport (Songandaprayer), to Speak Wisely (Smart Strike), a stakes winner in Canada, and to Sweet Talkin (Candy Ride), a winner at two and dam of Cavalry Charge, a Grade 3 winner who was Grade 2-placed.

Third dam Irene's Talkin (At the Threshold) won at two and had eight winners from eight runners.

Rainier has a yearling filly by Munnings and a filly foal of 2023 by Constitution, and she has been covered again by Speightstown.