We don't know that, but she has settled down mentally and is a high-class filly.
From the sport.uk.msn.com
The filly will now move up to a mile and a half at Epsom next month in the Oaks.
From the guardian.co.uk
The best finish to date was the 3-year-old French filly Jolypha's third in 1992.
From the courier-journal.com
There is going to be somebody who will say a filly shouldn't have been in there.
From the kentucky.com
Filly Rachel Alexandra, with Calvin Borel aboard, wins her eighth straight race.
From the washingtonpost.com
The last filly to try was Excellent Meeting, who failed to finish the 1999 race.
From the washingtonpost.com
That's when Rachel Alexandra became the first filly in 85 years to win the race.
From the fresnobee.com
She will be sold with a Casino Prince filly at foot and in foal to Lope De Vega.
From the couriermail.com.au
Janney's parents, Stuart Jr., and Barbara, owned the incomparable filly Ruffian.
From the newsday.com
More examples
A young female horse under the age of four
A female horse that has not yet given birth to any offspring, see Mare, e.g., "Sarah was given a filly and two foals from her grandfather's administrators."
A young female horse who has not yet had a foal between the ages of birth and 4 years.
A female horse age 3 or younger. Beginning at 4, they are called mares.