I agree. That's downright awful. When I have kids, I'm just going to buy them toys that look fun, regardless of their gender and regardless of the gender that the toy is marketed for.
I'd say the "Her First" part is the issue; but then that's not something the kids pick up on.
But, y'know, kids like playing with that stuff. Little girls especially. So... they're gonna sell it. I don't think me playing with Action Men (and definitely not any Barbies when I was 3... ahem) or toy guns reinforced anything particularly.
It is absolutely something kids pick up on. Maybe they don't read the words "Her first". But they see the pink packaging, pastel tones, commercials, and the little girl on the box, and they know exactly who this toy is "supposed to be" for. It isn't necessarily going to make little girls want to do housework all their lives, but it IS going to send them the message that it's what women should do. That it's something they should aspire to. Consciously or not, it will affect them.
It affects boys too. And demonstrating that is a no brainer. You said it yourself. "Definitely not any Barbies". Why not? Well, because Barbies are unquestionably marketed towards girls. And girls toys tend to be kinda lame compared to boys toys, just because toy companies think that girls will only like stereotypical stuff.
It's not that toys necessarily determine what a person will be interested in as an adult. But toys DO perpetuate gender stereotypes better than pretty much anything else.
And no matter how much parents try to teach their kids that men and women are equal, and that they can be whatever they want when they grow up, they're going to get the opposite messages from society. Even if parents buy them an equal mix of girl and boy toys, they're going to end up with more of their own gender's toys. Largely because of relatives who don't know what to get them.
So OP, I'm sure it doesn't even need to be said, but please get your niece something cool. =P