When I got Ahsoka, she had some runeword gear (Nadir helm, Stealth armor, Zephyr Stag Bow), and her act 2 mercenary was decked out similarly. One of the first item drops on the Foothills was an ethereal 2-socket flamberge, so after rescuing the barbs I switched to an Act 5 merc and equipped him with a Steel runeword in that. I later crafted him a blood helm for some life leech and deadly strike.
But what about her skills, you ask? When I received her, Ahsoka had 5 points in Freezing Arrow and 5 points in Valkyrie. She also had an extra point in Decoy, 5 points in Penetrate, and 11 in Critical Strike. I saw 2 logical options: choose the cold arrow synergy for a nice frost maiden that would then rely on her minions and a normal attack to deal with cold immunes, or go with mutlishot or strafe to take advantage of the already placed points into penetrate/critical strike. After leveling the Valk to 8 (she gets the lance then) and pumping Freezing arrow to a similar level, I decided to go with strafe. It really wasn't doing much damage with that 9-15 damage stag bow, and Ahsoka didn't see any item upgrades until I was getting ready to pass her.
She really needed a new weapon before nightmare, and by the end of the act I had a plain Razor Bow (from cow level), a rare Hunter Bow with the cruel suffix (234% ed) and a magic Hunter Bow with the evisceration suffix (+56 max damage or something insane). Both of the Hunter Bows were gambled. The problem I had was trying to decide how else I was going to upgrade her gear. She was still wearing normal belt and boots, and I had also gambled a nice 30 frw, 30 light res, 10 fhr and +mana pair of boots for personalization. She had a magic circlet gambled from earlier in the act with +5 min damage/+19 res all that I really wanted to socket. Lastly, I had +15 max and +12 max damage jewels. I thought about burning through a bunch of resources by socketing the Razor Bow in the cube, then turning it into a socketed magic item and re-rolling with chip gems until I got 2 sockets and a decent suffix roll, but that would require personalization, and she would still be using normal boots. I ended up socketing the circlet (everyone looks better in a circlet anyway), used the cube to socket the Razor Bow, and dumped my two damage jewels and a Shael rune into the bow. She fires super fast now, and has 2 customizable sockets in her helm that purplelocust will have to decide what to do with. I crafted her a safety belt from a demonhide sash that came out crap, but better than a plain plated belt.
Her resists are good, her merc and valk are reasonably strong, and with level 10 freezing arrow and a super fast strafe she should be fine for a while.
