how many feeds is she getting during the day?

babies change their sleeping habits so regularly, just as you were beginning to get used to one pattern they change and begin night waking etc, my girl is going on 8 months and the last week has been brilliant, prior to that we were all over the shop.

if i were you i would try feeding when she wakes then resettling, if she resettles fine an goes back to sleep then she's possibly hungry, and a 15 minute feed is a lot better than up every hour with the dummy (speaking from experience!!).... 3.5 months is still pretty young so i would probably try a feed and see if it makes any difference. its hard when they sleep thru and then stop isnt it?! you almost wish it had never happened as then you start trying to figure out why why why why did it end!

good luck let us know how u go....