Difficulty Feeding help pls.

Im
My baby girl used to take 90% of her bottle 6 times a day. Then she got pneumonia and had to reintubate her and stop oral feed. Now its been 3 weeks we having a hard time getting her back in track she barely finishes 1 bottle ones a day. Pls help me wat can i do??? Has anyone experienced this?? Fyi she is a 25 weeker. Pls help...