User blog comment:Kungfugi/Rosy, the Innocent Exterminator/@comment-83.117.176.180-20120130134210/@comment-4800808-20120201151807

When she ults and goes into stealth, it ends when she does an attack or ability. (also gets the passive from her W and hits with a crit). But If her W isn't on cooldown and an ally is close, she can jump into that right away.