Feeding baby!!!!

So my baby’s physician said hold off on oatmeal rice foe right now at her 4 month apt and to increase milk she was under weight. I have increased milk I give her bottles on top of breastfeeding her but she does not last long between bottles and she use to go about 4 hours she also used to sleep through the night and now wakes up

3 times which could be regression and growing. She looks at our food is very interested she hold her head up

Great and has sat up by herself for 45 seconds. She is exclusive BF and

They say 6 months but has anyone started them earlier if they are showing signs of wanting it/ needing it I know I’m suppose to give her the same amount of milk but I would try for her to go 3-4 house in between 5 oz bottles not every 2