Ukraine is the oldest of the three siblings, and is constantly getting dragged into some sort of mess. She is described by her brother as being very warm-hearted and motherly, having taken care of him and Belarus when they were little. She was the one who gave Russia his scarf, which he continues to wear today. Ukraine also shows maternal tendencies to other ex-Soviets, such as Poland, and to characters outside her family as well.
Russia also notes that she's a bit of a cry-baby and her heart is too big, making her an easy target. She desires to make friends in the West after her independence, but it appears she's struggling.
It is later stated in volume 3 notes and her volume 4 profile that despite her cry-baby appearance, she is also a 'fearsome' older sister and can stand her ground.
The Sealand and Latvia desktop mascot reveals that Ukraine is known for her surreal "guro" horror games.[2]