But her work on Tuesday has Richards confident she can win.
"She worked really well, she was too sharp for [race rival] Markus Aurelius," says Richards.
"We didn't see the best of her in the spring but I think she is really coming back to it and I think she can get away with 1600m second-up."
The 1600m might be a little short of Amarelinha's best distance but that is also probably the case for fellow mares House Of Cartier and Sinarahma, while it is almost certainly a stretch for big boys Mascarpone, Packing Rockstar and Vigor Winner.
The horses probably best suited by the mile are Brando, Markus Aurelius and Hasabro but they all have reasons (inconsistency, Tuesday's trackwork or South Island form) to give punters doubt.
"Brando had a confidence-boosting win last time so he is probably well suited while Markus Aurelius was coming up well until he didn't work that great on Tuesday.
"So they all have good chances but the mare is our best hope."
While that triple threat would be a strong hand for any stable in a Group race, Richards doubles down with an even stronger one in the $110,000 Matamata Breeders Stakes, the feature race of the year on Te Akau's home track.
With unbeaten Maven Belle, I Choose You and listed winner Hanalei in the race the stable could dominate, although Pacific Dragon from the Tony Pike stable is at least as well performed as Richards' trio and has a better draw.
If she can jump and run, the Richards trio will need to work hard to chase her down as Pacific Dragon beat Wolverine (subsequently relegated) two starts ago and was fifth in the Karaka Million.
But that means she has already had a harder summer than her three main rivals, all of who have had only two starts.
Richards says Imperatriz (R6, No 5) finds herself in an awkward place in the weights in the Lisa Chittick Plate, in which the filly carries 57kg, only one less than Showoroses and 1kg more than last-start Westbury Classic winner Dragon Queen.
"She is not suited at the weights but her big aim is the Levin Classic in three weeks and we really want to keep her to that three-week gap, which is why she is starting on Saturday. She can still win but it is less than ideal."
Richards suggests the stable has a strong hand in the support card races at Matamata but his best bet away from the black-type races could be at Ōtaki.
"Top Brass is a horse who is very well and while he meets a horse in career-best form in Stumpy we think he will go well."