Ravensdale Twins

This is one surname-name that may swing decidedly to the male side, thanks to highly-visible young actor Alden Ehrenreich.

Avery is a hugely popular name in the US, especially for girls. But while nearly four times as many girls as boys are named Avery today Avery's popularity is starting to soften for girls while it continues to strengthen for boys.

Very popular surname choice — it's in the Boys' Top 100 — beginning to catch on for girls. First female association: novelist Carson McCullers.

Once a common boys' name in Ireland (e. g. , Darby O'Gill and the Little People), the dynamic Darby now has a definite unisex feel. Actor Paul Rudd has a young daughter named Darby.

Delaney has been a popular Irish surname name for a couple of decades, projecting buoyant enthusiasm plus a feminine feel.

In the past few years Ellery has gone from middle-aged male detective to a plausible girls' name, a la Hillary.

The combination of Emily and Emma's popularity -- and the fact that Desperate Housewives star Teri Hatcher's daughter is named Emerson -- have put this formerly strictly boys’ name, embodying the gravitas of Ralph Waldo Emerson, in the limelight for girls.

This was a 100 percent boys’ name until celebs Jason Sehorn and Angie Harmon bestowed it on their daughter, recently followed by Lisa Marie Presley, who used it for one of her (female) twins. Finlay is also now among the most popular unisex names.

You might think of Harper as the hottest name of the last decade, jumping from obscurity to the Top 10, where it remained until last year.

This surname gained momentum in the 1990s, when it was particularly in vogue for males. However, it seems to be experiencing a surge for females—it was one of the fastest-rising names of 2013, jumping 266 spots back into the Top 1000.

Mason is a supertrendy name for boys that's starting to cross over -- Kelsey Grammer used it for his daughter. Creative speller's delight.

Morgan has long been a traditional Welsh male name, a variant of the Old Welsh name Morcant, from the Welsh elements mor, meaning "sea" and cant, "circle." The female Morgan is unrelated to the male version—it is a name from Arthurian legend created for Morgan le Fay, King Arthur's half-sister and famed sorceress. Her name comes from Morgen, an Old Welsh name meaning "sea-born," and is related to the Irish name Muirgen.

Indie actress Parker Posey put a female imprint on this sophisticated surname that's still about three times as common for boys but rising for both sexes. Parker has the advantage of its nature connection, relating it to such occupational names as Gardener and Forester.

Peyton is a unisex surname that's not only survived but continues to grow in popularity because of its rich southern-accented softness combined with the pre-Desperate Housewives naughtiness of Peyton Place. In recent years, more boys have been named Peyton thanks to football star Peyton Manning, but the projected film of William Styron's Lie Down in Darkness which features heroine Peyton Loftis may further popularize Peyton as a girls' name.

The sassy, steel magnolia appeal of Oscar-winning Reese (born Laura Jeanne—Reese is her mother's maiden name) Witherspoon has single-handedly propelled this formerly boys’ name into girls' popularity.

Riley—an upbeat, friendly surname name—is red hot for girls and still going strong for boys. If you haven't been spending much time around babies recently, you may be surprised to learn that Riley is the most popular girls' name starting with R and also the Number 1 Irish name for girls in the US.

Sawyer is one of the top unisex names, used for their daughters by such parents as Sara Gilbert, co-host of The Talk and former actress on Roseanne, currently on The Conners. Sawyer is is one of those newly-stylish occupational names that can work for either gender. If you want something with less brawn and more brains than Sawyer, try Sayer.

Sydney was a hot girls' name in the 1990s, but she's arguably still cool. One of the original old man names adopted for baby girls, Sydney's popularity may be down but she's not out.

Taylor is one of the prime unisex surnames used for girls and has also been a soap opera favorite. Taylor was in the Top 10 for the last several years of the twentieth century, so that now it tends to feel a little nineties – though Taylor Swift is keeping it in the spotlight and Tay is a charming nickname. Garth Brooks and Bryan Cranston have daughters named Taylor; Taylor Schilling portrays lead Piper Chapman in Orange is the New Black.