Pretty decent. She's taken a beating from a pissed off Lunatik and laughed the whole time, and he's basically Marvel's answer to Lobo. And she's also done fairly well in hsort confrontations with Silver Surfer and the Fallen One.
Was just rereading Thanos this evening, and it came to my attention that she is actually pretty powerful. When Thanos is talking with Starlord and Gladiator, Starlord notes that due to space limits, three Alpha class prisoners were stored and cocooned in their kyln, when there should only have been 1 per kyln. We know that one is the Maker (the person they're talking about), and we later learn that one was the Fallen One (whose cocoon was next to the Maker's), and we see the Maker release Skreet from her own cocoon next to the Maker's. That makes three (we never see another cocoon, and the fact that Skreet was imprisoned thusly, while the other non-Alpha prisoners are just given nanites and allowed to roam free and tend the kyln seems to point to the notion that she is, in fact, Alpha class.)
Interesting theory... but how they imply Fallen One wasn't the first herald?
He wasn't the big guy's Herald until long after T&A were imprisoned, but their conversation in SILVER SURFER #3 indicated that Galactus had been empowering mortals with the Power Cosmic back in their day.
Yup. She's a chaos mite, the original life form of the universe. Deemed too unstanble, the elders (Tenebrous, Aegis and their ilk) purged them from the universe. Skreet hid SOMEWHERE (I still say Taa II) and survived.