There was a period of time when HYDRA was losing leverage on Bucky. So what did they do? Give him a daughter and then deprive him of ever seeing her, that's what.

Every time he would do well on a mission, they gave him a moment, maybe 5 minutes if he was lucky enough, to chat with her.

Bucky ticked off the minutes in his addled mind as his boots resonated with the floor of the facility. Some doctorate official droned on about his next mission, but the words failed to stick in his mind, only focusing on the door that came into focus soon enough.

While Bucky was off on some mission on the other side of the globe, the kid had fallen sick, hence why they were reuniting in the medbay this time. The second his eyes locked on her, it was like a 600-pound truck had been lifted from his chest.