Based on the following strip, I'm pretty sure she's just crying theatrically, not throwing up. "Oeeeee" sounds more like the usual "wailing cry" sound effect than the "vomiting" one.
And you used to be so cute way back when...Kyaaaaaaaa!W-wait, don't cry!Well, excuse me for being smaller than you.Uuubbblllrrghhh!Yuuka-chan, you're so cold...Drunken FrenzyOh, no wonder--these are your clothes, Yuuka-chan!What the heck, Nee-san? You stink of alcohol. Hurry up and leave.