The Blessing of Many Fractures - S1-E8
Continuity mistake: During the fight with Zhou Cheng, Cheng does a forward flip and kicks Danny, making him stumble backwards. In the shot of Cheng lying on the ground, Danny is holding his stomach. In the shot immediately afterwards, he's holding his chest.
The Blessing of Many Fractures - S1-E8
Continuity mistake: When Danny offers Zhou Cheng money, the position of the money in Danny's hand changes between shots.
The Blessing of Many Fractures - S1-E8
Continuity mistake: During Colleen's sword fight, the position of her sword's sheath and her assailant's on the ground changes between shots.
Answer: Sokovia is a nation in the Iron Curtain. It is just as likely for a US operative to end up there as any of the other former Soviet nations. There is no reason to believe she was there at the same time as the Avengers. It was likely some form of covert mission there years beforehand.