Honestly, I wouldn't change and definitely not unless you've been advised to by a doctor who knows what they're talking about. Hungry baby forumla just tricks the body into thinking it is full but it doesn't give the baby as many calories for the same volume of milk. So it may be more convenient for you because you won't have to feed her as often but you'll really be taking away calories your baby needs. If baby is hungry, she needs calories (unless you think she isn't really hungry and is doing something like comfort sucking, in which case you could consider alternatives to the bottle).
Instead, could you try increasing the amount in each bottle so she might go a bit longer between feeds, especially overnight? Some babies cluster feed in the evening, so lots of feeds closer together to stock up for overnight. And some babies do just like to feed every 2 hours, but it does get better as they get older. Your baby is still very young so I would be expecting to feed her that often for a while yet really.
