J.S.
I agree with the other posts that suggest she might be teething or have some other temporary disruption. My now 18 month old has been through several of these "phases" and with each of them I was just like you - paranoid it would be a new permanent pattern - but my mother was right and it never was. She advised me to tend to her if she cries and needs me - after all they are only little for such a short time and grow up so quickly. THere was a period of time when my little one was about 10-13 months old that she refused to go to sleep unless I was there in the room - I laid beside the crib every night and snuck out after she was asleep. And then one night she was fine! Before that she had been sleeping well through the nights most nights. I am rambling, but my point is that from my experience, it's worth tending to her needs and it will pass.