Kindred is a jungling ADC, which means she has all of the damage potential of a normal ADC with the unpredictability factor of a roaming jungler. Her kit is also HIGHLY focused on attack speed and getting out a high crit rate. Rapid Firecannon and such are all very good items for her as they boost attack speed and crit rate.
She doesn't need BoRK either as her E has some %health damage in it already under certain variables, and she's more likely to build mortal reminder or Lord Dom Regard over black cleaver.
Honestly though, she's SUPER squishy if you CC her. Like, I'm not even joking dead in two seconds squishy. The problem is getting close enough to actually DO that if you allowed her to get 10+ stacks... because every 3 mark stacks after her 4th mark adds to her autoattack range. At 25 marks she has an aa range of 750. That's over half the range of Caitlyn's ult (1300).
One solution is to shut her down early game, when she is squishy and has no items. Another is a good long chainstun/CC combo. Like with any carry, though, she becomes a MONSTER when she has enough gold to build.
Also, for lifesteal she's more likely to roll Bloodthirster for the extra damage to make her crits hit that much harder than any other source of lifesteal.