I am dating a 5w6 and I wouldn't consider gift-giving a strong point at all. But I think this could be individual. I'd say the very best way to determine if a 5 cares for you, is if they are around. Seriously, it ain't much for us needier, valiation-seeking types.. but I've had this talk with my 5 over and over, and to him is it really fucking simple. If he didn't like me, he wouldn't be around. He absolutely despises any kind of expectation, and refuses to act on it, because they basically refuse to be inauthentic, ever. The best way to get love from a 5 is to give them ALL THE FREEDOM in the world. Very little expecatation, and try to keep emotionalism at bay. 5w6 shows love through time spent, and physically. They suck at verbalizing and aren't big on gift giving either. Acts of service can *sometimes* be shown.
Edit: Now I think about it, Nerdgirl, I think it's very possible a 5 might be different with children, assuming that as they age they develop inferior Fe more. I would imagine an older 5 could be alot more affectionate than when younger.