I'm not sure if there's a "too early" for my cat or if he just will always do this, because I've never managed to give him attention long enough that he's satisfied. A minute, ten minutes, an hour...
My other cat actually seems pretty similar to her in that regard; she's super food motivated (begging constantly for literally anything edible, even human food like fries or ramen noodles, although of course we don't give her any), but she also demands pets and rubs the point where she seems like she's overstimulating herself. Although she'll happily settle on literally anyone's lap (even a stranger), if you pet her more than a little bit, she'll slowly start to lick your fingers, and then if you don't withdraw them give them a nibble, and then just absolutely chomp on them, all while refusing to budge off your lap. Sometimes she'll just go right from headbutting to chomping, and it doesn't actually seem like she's unhappy with the sensation or anything; she just gets excited and enjoys biting our hands as much as getting pet by them (or maybe even a bit more...).
She's pretty weird in a lot of ways though, and I suspect a big part of it is a lack of proper socialization before I adopted her. When I got her from a shelter, she was already 10 years old, and they evidently didn't keep their records super carefully, since I was initially told she wasn't spayed over, then told in person she was spayed and given documentation indicating that, but she definitely wasn't! She kept going into heat, which can apparently still happen after being spayed if they accidentally leave behind a small amount of ovarian tissue, so my vet had me get her into surgery right when she had started going into heat at one point so that the leftover tissue would be swelled and easier to remove, but the surgeon told me after that she had definitely never actually been spayed before; her words were something along the lines of "I opened her up, and then BAM, uterus!"
In addition to her infinite appetite for things she has no business being interested in and her violent cuddling tendencies, she's also the only cat I've ever known to run _towards_ loud sounds when something falls over or something. She's even growled menacingly at sounds in the hallway on more than one occasion; I think she thinks she's a guard dog or something.
You'll only know which it was based on whether she chases you after you've got a new scratch and walked away or not!