Talk to Pediatrician on Best Formula Milk For 8 Month Old Girl.

Assalam o Alaikum. My daughter will be turning 8 months old in a week's time, InshaAllah. She was on her mother's feed only till 5.5 months. Then we introduced her on solids. I haven't started her on formula milk yet. Since about a week, she is hardly drinking any milk. She hasn't gained much weight since she turned 6 months. At 6 months, she weighed 7.9 kg and she weighs 8.2 kg now. Another thing is that she is otherwise quite active during the day MashaAllah but doesn't sleep properly at night. She keeps on waking up after every hour or so. What could be the reason and how to handle this? Can you also please guide that which formula milk should I start her on to supplement her diet?

Thank you so much.