Betta Fish: Help my betta’s tummy is big

Hi guys i dont exactly know whats wrong with my betta Bubbles. Bubbles is in a tank with some mollies and one of the mollies (i didnt know cuz i was away for some time) got pregnant and gave birth. my friend (who was taking care of bubbles at the time) told me that he only saw 2 baby mollies. So my guess is that bubbles ate the babies which is why her tummy got big. i tried separating her in a hospital tank for 2 weeks— sometimes with almond leaves or with aquarium salt. well shes still swimming around and eating but she’s having a hard time swimming cuz of her tummy. what can i do to help her? thank you so much. btw she’s 3 years old