I have had a very rare occasion where a hen had a bloaty abdomen and with a round of antibiotics, she got completely better and went on to survive and lay eggs regularly again. That one hen was my splash Ameraucana hen, Snow.
The bad news is that many do seem to get better for a time, but they usually never lay eggs again and eventually, they die, even if they never have a bloated abdomen again. I just lost my beautiful blue barred EE, Riley, exactly that way. Her abdomen was back to normal for quite some time, but she never really seemed quite her perky self and she never laid another egg. This went on for several months and a few weeks ago, found her dead under the roost. As I carried her to bury her, her abdomen seemed slightly poochy again, like fluid was just beginning to build again. She was laying internally or had ovarian cancer--hard to say, because, this time, we didn't have the heart to open this hen up and look. We've seen it so many times already, we knew what we'd find.
Btw, I did not drain Riley and I rarely drain unless the abdomen unless it's as large as a bowling ball like my Olivia's was.
These threads may be helpful to you.
What antibiotic did you treat her with? How much daily and how long please?? Pleas explain...