Broken sleep again :(

Just when I thought Isabella was getting the hang of night time sleeping we seem to be going backwards. Rather than the usual 5-6 hours overnight she has only been managing 4 for the last few nights. Last night was particularly disturbed. She fed at midnight, 4am, 6am and again at 9am. I'm wondering if it's another growth spurt coming on? She also seems to be splitting her day time feeds up again. Rather than going the usual 3 hours between feeds she's back to doing every hour and a half. While I don't mind the regular feeding during normal waking hours, I'm not so thrilled by the night time ones! While she manages to drop straight back to sleep after her feed, it will take me up to half and hour or more to sleep again, only to be woken an hour later for more food. I'm hoping it's just a phase and we'll be back to longer sleeps again soon...please! I'm still toying with the idea of giving her a bottle of formula food before bed to see if that helps her sleep longer, but I'm still a bit loathed to do it.