4 months is one of the periods where babies could be expected to go through a growth spurt.
You can refer to this article on a description of what a baby is likely going through at this stage:
http://www.secretsofbabybehavior.com/2009/10/infant-development-4-5-months.html
Therefore, it is expected that a baby will appear to be feeding more. I have read that baby will stop drinking when they are full. Hence, if you are bottle feeding, be sure to watch out for signs that your baby is full and seemed to want to push away her bottle. If she did not display signs that she has had enough, you need not be too worried about her drinking too much.
Hope this helps!
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