Could be Silent Reflux - there are some simple things you can try. Sit her upright during and after feeding, try to keep het still for 15-30 mins after a feed, to let her milk go down. Raise the head of her moses basket/cot so that her head is a little higher than her feet. There are also different bottles and teats that claim to help with reflux. If these things don't help you could take her the doctor, if he thinks its reflux he may prescribe infant gaviscon, if this still doesn't work there are other medications than can be tried.
Also one brand of formula may work well for one child but not another - we tried SMA gold, Sma Staydown, sma wysoy and cow and gate before we finally found Nutramigen, which worked for our daughter. Obviously you should discuss any change of diet with your HV or Dr.
Our daughter had very bad reflux, but it wasn't silent (silent means no vomitting) So I speak from experience. Unfortunately it really is just a case of trial and error, to find out what works, but things do and will get better! Good luck!