Can you take her temperature and see if she has a mild fever?
She might have a bit of a cold which can cause unsettledness.
if she's rubbing her ears might be ear infection

it could be teething though. when DS was teething he was better during the day - more distractions ? - but very bad at night. Crying, hard to resettle after a feed, very frequent wakings. This was in combination with a cold though! not fun.

i did find that DS's sleep habits chnaged at around the 4 month mark. it might be a development thing.