Hinata appears in her regular outfit before the Fourth Shinobi World War in Naruto Shippuden. Her outfit consists of a loose fitting, long-sleeved, lavender and cream zip-up jacket with lavender cuffs over mesh armour with navy blue pants and black, and low-heeled sandals.
Hinata, as a purple ninja, would be considered having an average HP and a decent attack. Upon reaching Level 20, Hinata can learn the Eight Gates, which gives allies within a 3x3 square area of her plus 130 attack power for 2 turns. She is more defense-oriented rather than attack-based, so she will have a higher HP than some other purple taijutsu ninjas.
Like with all purple ninja, you can keep Hinata as one of your ninjas until your village reaches Level 20, in which case you should start receiving red ninjas. Before that though, Hinata can be used as a tanker at relatively high levels (Levels 15+), and take hits for your punishers. You should keep her in the front line so that enemies would go attack her first, and then your punishers would take out the opponent's forces. After Level 20, consider passing on her EXP to one of your more powerful ninjas.
Hinata is available in Purple Ninja Packs, which are quite common in the game. You can get them by gaining 30 Active Points in one day, where it's in the chest. You can also get it at Hinata's Storage Box, where it is always a prize, though it is relatively difficult to win. Also, Ninja Saga can be used to obtain Hinata when your village is at least Level 30, though it is more likely that you'll get her to obtain the free golden ninja later when your village reaches Level 45.