Gaining weight — What options?

Is it “un-African” to be a slim girl? I ask because I was talking to an old friend of mine a couple of days ago. She’d seen a picture of moi on FB with like 10 kg extra from my suffering University years and was lamenting that she had stayed the same weight over all the years..

Apparently the big issue was that at some Houston party, some dude tried to “toast” her by saying she looked like his younger sister who was still in High School.. Quite rightly, my friend was indignant especially considering she’s 28ish at the moment and the dude in question was barely out of college. Her solution to that is that she needs to bulk up and “push out a bit of hips n backassi” to “look slightly like my ancestors”. Unfortunately, I have acquired a reputation for dispensing advice (although I don’t take my own advice), so her question was what options did she have for bulking up…

Personally i feel she’s ok…. She 5′-10″ and weighs 142 pounds.. Guess that works out to a BMI of about 20ish……. So blogsville people, what are her options??????

Edit… As GNG pointed out its 142 lbs not stone!