Talk to Pediatrician on Weight Gain Issue, Vaccination

Asslam-O-Alaikum!

My baby has a clef palate. Her age is 3 months. We are extremely worried because her weight has been steadily declining since her birth. Her weight was 3.6 or 3.8 kg when she was born. Her weight is, now, is lower than that. Please help us. Tell us how we can help her recover and expand her weight. Due to cleft palate, unfortunately, she is not able to suck her mother's breast. Doctors so far we have consulted say that she should be fed mother's milk, although that is not possible. So we feed her formula milk. Please guide us. There is another question I would like you to answer, too. My child got her first vaccination after a month's delay because it was not able due to strike. Her second vaccination dose has been delayed by us. Reason being she would gain fever after it, and that would further worsen her weight issue. Should we or should we not move ahead for second dose of vaccination regardless of weight issue. Please guide. Furthermore, we are told that clef